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Question 1United States History
Which document begins with the words "We the People" and outlines the structure of the federal government of the United States?
- The Constitution of the United States Correct answer.
- The Articles of Confederation
- The Declaration of Independence
- The Bill of Rights
Explanation
The Preamble to the Constitution opens with "We the People of the United States" and the document then establishes the legislative, executive, and judicial branches. The Declaration of Independence is a statement of grievances against Britain, while the Articles of Confederation preceded the Constitution.
Question 2United States History
The Declaration of Independence draws most heavily on which idea associated with John Locke?
- Political power should be concentrated in a single hereditary ruler
- Governments derive their authority from the consent of the governed Correct answer.
- Judges should hold their offices for life during good behavior
- Property ownership should be abolished in a republic
Explanation
Locke argued that people possess natural rights and that government rests on the consent of the governed, and the Declaration echoes this in its claim that governments derive "their just powers from the consent of the governed." The other statements describe ideas contrary to Locke or unrelated to him.
Question 3United States History
Under the Great Compromise reached at the Constitutional Convention of 1787, how was representation in Congress structured?
- Representation was based on state land area in both houses
- The House was apportioned by population, while the Senate gave each state equal representation Correct answer.
- Population determined representation in both houses
- Each state received equal representation in both houses
Explanation
The Great Compromise blended the Virginia Plan's population-based representation with the New Jersey Plan's equal state representation. The result was a bicameral Congress: a House apportioned by population and a Senate with two members per state.
Question 4United States History
Which principle of the U.S. Constitution is illustrated by the president's power to veto legislation passed by Congress?
- Checks and balances Correct answer.
- Federalism
- Popular sovereignty
- Judicial review
Explanation
Checks and balances refers to the ability of each branch to limit the powers of the others. The veto lets the executive block acts of the legislature, and Congress can override it with a two-thirds vote.
Question 5United States History
The First Amendment protects which set of freedoms?
- Protection against self-incrimination and double jeopardy
- Religion, speech, the press, assembly, and petition Correct answer.
- The right to a speedy and public trial by jury
- The right to bear arms and quarter soldiers
Explanation
The First Amendment bars Congress from establishing a religion or abridging free exercise, speech, press, assembly, and the right to petition the government. The other listed protections appear in the Second, Third, Fifth, and Sixth Amendments.
Question 6United States History
Which Supreme Court decision established the principle of judicial review?
- Plessy v. Ferguson
- McCulloch v. Maryland
- Marbury v. Madison Correct answer.
- Dred Scott v. Sandford
Explanation
In Marbury v. Madison (1803), Chief Justice John Marshall held that a law conflicting with the Constitution could not be enforced, establishing that courts may review acts of Congress. The other cases addressed slavery, segregation, and federal banking powers.
Question 7United States History
Which action by the federal government during Reconstruction was intended to protect the civil rights of formerly enslaved people?
- Establishing the Freedmen's Bureau's closure
- Issuing the Emancipation Proclamation
- Passing the Black Codes
- Ratifying the Fourteenth Amendment Correct answer.
Explanation
The Fourteenth Amendment, ratified in 1868, granted citizenship to all persons born or naturalized in the United States and guaranteed equal protection and due process. It became the constitutional foundation for later civil rights litigation.
Question 8United States History
The Louisiana Purchase of 1803 had which effect on the United States?
- It transferred Florida from Spain to Britain
- It roughly doubled the size of the nation Correct answer.
- It ended the War of 1812
- It granted statehood to California
Explanation
The purchase from France added about 828,000 square miles west of the Mississippi River, roughly doubling U.S. territory. It opened the region to westward expansion and exploration, including the Lewis and Clark expedition.
Question 9United States History
Which factor most directly contributed to the growth of U.S. industrial output in the late nineteenth century?
- A decline in the number of railroad miles built
- Sharp reductions in immigration to the United States
- Federal policies that discouraged investment in manufacturing
- Expansion of the railroad network and abundant natural resources Correct answer.
Explanation
Railroads linked raw materials to factories and factories to markets, while coal, iron ore, and other resources fueled production. Immigration supplied much of the labor force, and federal policies such as protective tariffs and land grants generally encouraged industrial growth.
Question 10United States History
A historian argues that the Progressive Era changed the role of the federal government. Which development best supports this argument?
- The creation of the Federal Reserve System in 1913 Correct answer.
- The withdrawal of federal regulation of food and drugs
- The repeal of the Sherman Antitrust Act
- The elimination of the income tax
Explanation
The Federal Reserve Act of 1913 created a central banking system to regulate the money supply and stabilize the economy, an example of expanded federal economic authority. Progressive reforms generally increased regulation rather than removing it.
Question 11United States History
The main purpose of the Chinese Exclusion Act of 1882 was to
- grant citizenship to Chinese immigrants
- restrict immigration from China Correct answer.
- encourage Chinese laborers to settle in the West
- open new ports to Chinese trade
Explanation
The Chinese Exclusion Act suspended the immigration of Chinese laborers and was the first major federal law to restrict immigration by nationality. It reflected nativist pressures on the West Coast and remained in force in various forms for decades.
Question 12United States History
Which event is most often cited as the immediate trigger for the United States' entry into World War I in 1917?
- The signing of the Treaty of Versailles
- The Zimmermann Telegram and unrestricted submarine warfare Correct answer.
- The attack on Pearl Harbor
- The sinking of the Lusitania in 1915
Explanation
Germany's resumption of unrestricted submarine warfare and the intercepted Zimmermann Telegram, which proposed a German alliance with Mexico, pushed the United States to declare war in April 1917. The Lusitania sinking was an earlier factor but did not lead to immediate entry.
Question 13United States History
Which New Deal program was designed to provide retirement income for older Americans?
- The Tennessee Valley Authority
- The Agricultural Adjustment Act
- The Social Security Act Correct answer.
- The Wagner Act
Explanation
The Social Security Act of 1935 created a federal system of old-age pensions, unemployment insurance, and aid to dependent children. It remains a central feature of the American social safety net.
Question 14United States History
The internment of Japanese Americans during World War II was upheld by the Supreme Court in which case?
- Schenck v. United States
- Brown v. Board of Education
- Gideon v. Wainwright
- Korematsu v. United States Correct answer.
Explanation
In Korematsu v. United States (1944), the Court upheld the exclusion of Japanese Americans from designated areas, a decision widely criticized today and later repudiated. The other cases dealt with school segregation, wartime speech, and the right to counsel.
Question 15United States History
Which development best explains the postwar economic boom in the United States between 1945 and 1960?
- The elimination of the GI Bill
- A sharp decline in consumer spending
- A return to prewar levels of industrial production
- Federal spending on highways, housing, education, and defense Correct answer.
Explanation
Government spending on the interstate highway system, suburban housing, education through the GI Bill, and Cold War defense stimulated demand and employment. Consumer spending also rose sharply rather than declining.
Question 16United States History
The Supreme Court's decision in Brown v. Board of Education (1954) held that
- school prayer was unconstitutional
- racial segregation in public schools violated the equal protection clause Correct answer.
- busing to achieve integration was forbidden
- states could set separate but equal school systems
Explanation
Brown overturned Plessy v. Ferguson's "separate but equal" doctrine in public education, holding that segregated schools are inherently unequal and violate the Fourteenth Amendment's equal protection clause. It became a cornerstone of the civil rights movement.
Question 17United States History
The Montgomery Bus Boycott of 1955-1956 succeeded primarily because
- the city voluntarily desegregated buses without litigation
- the economic pressure of boycotting riders led to a court ruling against segregation Correct answer.
- the federal government seized the bus system
- Congress passed a law ending segregation nationwide
Explanation
African Americans refused to ride city buses for over a year, causing severe revenue losses, while the legal challenge proceeded through the courts to the Supreme Court's ruling in Browder v. Gayle. The combination of economic pressure and litigation ended segregated bus seating.
Question 18United States History
Which statement best describes the purpose of the Interstate Highway System authorized by the Federal Aid Highway Act of 1956?
- To fund only local city streets
- To replace railroads entirely for freight transport
- To restrict automobile travel between states
- To connect major cities with a national network for defense and commerce Correct answer.
Explanation
The act created a national system of limited-access highways justified by both civilian commerce and Cold War civil defense needs. It transformed transportation, suburban growth, and the American economy.
Question 19United States History
The Gulf of Tonkin Resolution of 1964 was significant because it
- ended U.S. involvement in Vietnam
- declared war on North Vietnam
- created the United Nations
- authorized the president to take military action in Southeast Asia Correct answer.
Explanation
The resolution gave President Johnson broad authority to use military force in Southeast Asia after reported attacks on U.S. ships. It functioned as a congressional authorization for escalation without a formal declaration of war.
Question 20United States History
Which of the following best illustrates the system of federalism in the United States?
- The Supreme Court hears appeals from lower courts
- States set their own speed limits while the federal government sets national emissions standards Correct answer.
- The president appoints cabinet secretaries
- The Senate confirms judicial nominees
Explanation
Federalism divides authority between the national government and the states, and each level exercises distinct powers. Speed limits set by states alongside federal emissions standards show this division of responsibility.
Question 21United States History
In Federalist No. 10, James Madison argued that a large republic would
- require a single dominant religious group
- control the effects of factions by multiplying competing interests Correct answer.
- abolish the need for representative government
- be more likely to be torn apart by factions
Explanation
Madison contended that an extended republic would contain many competing factions, making it difficult for any one to dominate. This argument supported ratification of the Constitution and the principle of pluralism.
Question 22United States History
Which interpretation of the Constitution did Alexander Hamilton defend in his argument for a national bank?
- Loose construction, allowing Congress to use implied powers to carry out its enumerated duties Correct answer.
- The view that the president alone may charter corporations
- The view that states may nullify federal laws
- Strict construction, limiting Congress to explicitly listed powers
Explanation
Hamilton relied on the Necessary and Proper Clause to argue that Congress could charter a bank as a means of carrying out its enumerated powers such as taxing and regulating commerce. The Supreme Court adopted this reasoning in McCulloch v. Maryland.
Question 23United States History
A student claims that the Articles of Confederation failed mainly because the national government lacked the power to tax. Which additional weakness most directly supports that same theme of a weak central government?
- The national government could override state laws at will
- The national government had a powerful executive branch
- The national government had an army that was too large
- The national government could not regulate interstate commerce Correct answer.
Explanation
Under the Articles, Congress could not levy taxes or regulate commerce among the states, leaving the national government dependent on state contributions and unable to address trade disputes. These limitations led to the Constitutional Convention of 1787.
Question 24United States History
Which of the following best explains why the Great Migration of African Americans from the South to northern cities accelerated during World War I?
- Southern states passed laws encouraging Black residents to leave
- Demand for industrial labor increased while southern agriculture offered few opportunities Correct answer.
- Northern states guaranteed full racial equality in housing and employment
- The federal government forcibly relocated African American families
Explanation
Wartime production created labor shortages in northern factories, while sharecropping, low wages, and racial violence pushed many African Americans to leave the South. The migration reshaped urban populations and culture in the North.
Question 25United States History
Which constitutional provision was most directly used to justify the Supreme Court's decision in Brown v. Board of Education?
- The necessary and proper clause
- The commerce clause
- The equal protection clause of the Fourteenth Amendment Correct answer.
- The establishment clause of the First Amendment
Explanation
Brown held that racially segregated public schools denied African American students equal protection of the laws under the Fourteenth Amendment. The Court concluded that separate educational facilities are inherently unequal.
Question 26United States History
The Mayflower Compact of 1620 is significant in United States history primarily because it
- created a bicameral legislature for the colony
- established a framework for self-government based on consent of the governed Correct answer.
- declared independence from the British Crown
- guaranteed religious freedom for all settlers
Explanation
The Mayflower Compact was an agreement among the Pilgrims to form a civil body politic and enact just laws for the general good. It reflected the idea that government derives its authority from the consent of the governed, a principle later central to American constitutional thought. It did not declare independence, create a legislature, or guarantee religious freedom.
Question 27United States History
Which principle from the Declaration of Independence most directly influenced later arguments for expanding voting rights?
- The idea that governments derive their just powers from the consent of the governed Correct answer.
- The assertion that property ownership is a requirement for citizenship
- The belief that a strong executive is necessary to maintain order
- The claim that judicial review is essential to protect liberty
Explanation
The Declaration of Independence states that governments are instituted among men, deriving their just powers from the consent of the governed. This principle underpins the argument that citizens have a right to participate in choosing their representatives. It has been used by movements seeking to expand the franchise to groups previously excluded.
Question 28United States History
Shays' Rebellion (1786–1787) contributed to the calling of the Constitutional Convention because it
- led directly to the adoption of the Bill of Rights
- demonstrated the need for a standing army to defend the frontier
- exposed the weakness of the national government under the Articles of Confederation Correct answer.
- convinced states to lower taxes on farmers
Explanation
Shays' Rebellion was an armed uprising of Massachusetts farmers facing debt and foreclosure. The national government under the Articles of Confederation could not raise troops or funds to respond effectively, which alarmed leaders and spurred momentum for a stronger central government. The event highlighted the inadequacies of the Articles.
Question 29United States History
The Three-Fifths Compromise, reached during the Constitutional Convention of 1787, concerned the
- selection of the president by the Electoral College
- method for admitting new states to the Union
- regulation of interstate commerce
- counting of enslaved people for purposes of representation and taxation Correct answer.
Explanation
The Three-Fifths Compromise resolved a dispute between slave and free states by agreeing that three-fifths of the enslaved population would be counted for both representation in the House of Representatives and for direct taxation. It did not address commerce, the Electoral College, or state admission.
Question 30United States History
Which action by President Thomas Jefferson most significantly expanded the territory of the United States?
- The establishment of the Bank of the United States
- The Lewis and Clark Expedition
- The Louisiana Purchase Correct answer.
- The Embargo Act of 1807
Explanation
The Louisiana Purchase of 1803 doubled the size of the United States by acquiring a vast territory from France. The Embargo Act was an economic policy, the Lewis and Clark Expedition was an exploration of the newly acquired land, and the Bank was a financial institution. Only the purchase itself expanded national territory.
Question 31United States History
The Missouri Compromise of 1820 was significant because it
- granted women the right to vote in territorial elections
- established the principle of popular sovereignty in all new territories
- maintained a balance between slave and free states by admitting Missouri as a slave state and Maine as a free state Correct answer.
- abolished slavery in all territories north of the 36°30' parallel
Explanation
The Missouri Compromise admitted Missouri as a slave state and Maine as a free state, preserving the balance in the Senate. It also prohibited slavery in the Louisiana Purchase territory north of 36°30' except Missouri. It did not abolish slavery everywhere, grant women suffrage, or apply popular sovereignty to all territories.
Question 32United States History
The Emancipation Proclamation of 1863 was limited in its immediate effect because it
- applied only to enslaved people in Confederate-held territory, not to slave states loyal to the Union Correct answer.
- exempted all border states and all Confederate states
- required a constitutional amendment before taking effect
- was struck down by the Supreme Court
Explanation
The Emancipation Proclamation declared freedom for enslaved people in states in rebellion, but it did not apply to slave states that had remained loyal to the Union or to areas already under Union control. Its immediate impact was therefore limited, though it changed the war's purpose and allowed African American men to serve in the Union army.
Question 33United States History
The Sherman Antitrust Act of 1890 was intended to
- regulate the railroad industry by setting maximum rates
- establish a national bank to stabilize the currency
- provide pensions for Union veterans of the Civil War
- curb the power of large monopolies and trusts that restrained trade Correct answer.
Explanation
The Sherman Antitrust Act was the first federal legislation to prohibit monopolies and restraint of trade. It aimed to break up combinations that stifled competition. Railroad regulation came with the Interstate Commerce Act, the national bank was established earlier, and veterans' pensions were separate legislation.
Question 34United States History
Which of the following best describes the purpose of the Dawes Act of 1887?
- To grant Native Americans immediate U.S. citizenship and voting rights
- To divide tribal lands into individual allotments and encourage Native Americans to adopt farming Correct answer.
- To provide federal funding for Native American schools that taught native languages
- To establish reservations where Native Americans could maintain traditional customs
Explanation
The Dawes Act, also known as the General Allotment Act, aimed to assimilate Native Americans by breaking up tribal lands into individual plots for farming. It sought to replace communal landholding with private property and Euro-American farming practices. It did not preserve traditional customs, grant immediate citizenship, or fund native-language schools.
Question 35United States History
The Open Door Policy, proposed by the United States in 1899, primarily sought to
- limit Chinese immigration to the United States
- ensure equal trading rights for all nations in China Correct answer.
- create a military alliance with Japan against Russia
- establish American colonies in Southeast Asia
Explanation
The Open Door Policy, articulated by Secretary of State John Hay, called for equal commercial access to China for all foreign powers and respect for Chinese territorial integrity. It was not about acquiring colonies, restricting immigration, or forming a military alliance.
Question 36United States History
The Zimmerman Telegram, intercepted in 1917, influenced American public opinion toward entering World War I because it
- announced Germany's intention to sink all neutral ships without warning
- disclosed a British plan to blockade American ports
- revealed a German proposal for Mexico to join the war against the United States Correct answer.
- showed that Russia had signed a separate peace with Germany
Explanation
The Zimmerman Telegram was a secret German message proposing that Mexico ally with Germany and, in return, recover territory lost to the United States. Its publication inflamed American opinion and helped build support for war. Unrestricted submarine warfare was a separate issue, and the other options are factually incorrect.
Question 37United States History
The Harlem Renaissance of the 1920s is best described as
- a political movement to secure voting rights in the South
- a flowering of African American literature, music, and art centered in New York City Correct answer.
- an economic program to rebuild northern cities after the Civil War
- a religious revival that swept through rural America
Explanation
The Harlem Renaissance was a cultural movement that produced notable African American writers, artists, and musicians, such as Langston Hughes and Zora Neale Hurston. It celebrated Black identity and contributed to a broader awareness of African American culture. It was not primarily a voting rights campaign, an economic reconstruction program, or a rural religious revival.
Question 38United States History
The Lend-Lease Act of 1941 was a significant departure from previous U.S. policy because it
- prohibited American banks from lending to foreign governments
- allowed the president to provide war materials to nations whose defense was vital to the United States Correct answer.
- required the United States to declare war on Germany immediately
- established a military alliance with the Soviet Union
Explanation
The Lend-Lease Act authorized the president to lend or lease military supplies to countries fighting the Axis powers, effectively ending the cash-and-carry requirement and supporting Britain and later the Soviet Union. It did not declare war, create a formal alliance, or prohibit loans.
Question 39United States History
The Truman Doctrine, announced in 1947, was based on the principle that the United States should
- provide economic aid only to countries in the Western Hemisphere
- return to a policy of isolationism in world affairs
- form a permanent military alliance with Western European nations
- support free peoples resisting subjugation by armed minorities or outside pressures Correct answer.
Explanation
The Truman Doctrine pledged American support for nations threatened by communism, specifically Greece and Turkey, and marked a shift toward a policy of containment. It did not advocate isolationism, create a permanent alliance (that was NATO), or limit aid to the Western Hemisphere.
Question 40United States History
The Civil Rights Act of 1964 was a landmark law because it
- guaranteed the right to vote for all citizens regardless of race
- prohibited discrimination based on race, color, religion, sex, or national origin in public accommodations and employment Correct answer.
- established the policy of affirmative action in federal hiring
- ended the poll tax in federal elections
Explanation
The Civil Rights Act of 1964 outlawed segregation in public places and banned employment discrimination on the basis of race, color, religion, sex, or national origin. Voting rights were addressed more directly by the Voting Rights Act of 1965, and the poll tax was abolished by the Twenty-Fourth Amendment. Affirmative action was not established by this act.
Question 41United States History
The Watergate scandal led to which constitutional consequence?
- The passage of a constitutional amendment limiting presidential terms
- The resignation of President Richard Nixon under threat of impeachment Correct answer.
- The impeachment and removal of President Richard Nixon from office
- The Supreme Court ruling that executive privilege is absolute
Explanation
President Nixon resigned in 1974 after the House Judiciary Committee approved articles of impeachment and the Supreme Court ordered him to release tape recordings. He was not impeached by the full House or removed by the Senate. The scandal did not produce a term-limits amendment or an absolute executive privilege ruling.
Question 42United States History
The Montgomery Bus Boycott of 1955–1956 succeeded primarily because
- the Supreme Court ruled that segregation on buses was unconstitutional before the boycott began
- the boycott was led by white business owners seeking to integrate the buses
- the African American community sustained a year-long economic boycott that forced the bus company to change its policies Correct answer.
- the federal government immediately sent troops to desegregate the buses
Explanation
The Montgomery Bus Boycott was a mass protest in which African Americans refused to ride city buses for over a year, causing severe economic pressure. The Supreme Court ultimately affirmed that bus segregation was unconstitutional in Browder v. Gayle. The boycott demonstrated the power of nonviolent economic protest.
Question 43United States History
Which statement best explains why the Great Migration of African Americans from the South to northern cities accelerated during World War I?
- Northern cities had no history of racial discrimination
- Northern factories needed workers, and African Americans sought to escape racial violence and Jim Crow laws Correct answer.
- Southern states encouraged African Americans to leave to reduce competition for jobs
- The federal government offered free land to African Americans who moved north
Explanation
The Great Migration was driven by a combination of push and pull factors: industrial jobs opened in northern cities due to wartime production, while African Americans faced continued violence, disfranchisement, and segregation in the South. The other options misstate the incentives or exaggerate conditions in the North.
Question 44United States History
The Articles of Confederation, in force from 1781 to 1789, gave the national Congress the power to
- levy taxes directly on individual citizens
- establish a national court system with broad jurisdiction
- declare war and conduct foreign affairs Correct answer.
- regulate interstate and foreign commerce
Explanation
Under the Articles, Congress could declare war, send diplomats, and manage relations with other nations, but it had no power to tax individuals, regulate commerce, or create a federal judiciary. These gaps, especially the lack of taxing and commerce power, were the central complaints that drove the 1787 convention.
Question 45United States History
In Federalist No. 10, James Madison argued that a large republic would better control the dangers of faction than a small one because
- a large territory would contain many competing interests, making it hard for any one faction to dominate Correct answer.
- a large republic would have a standing army to suppress unrest
- a large republic would concentrate power in a single national legislature
- a large republic would eliminate the need for political parties
Explanation
Madison reasoned that extending the republic over a wide territory multiplies the number of competing economic and religious interests, so no single faction is likely to form a majority capable of oppressing the rest. He did not claim factions could be abolished, only that their effects would be diluted.
Question 46United States History
Marbury v. Madison (1803) established which principle in American constitutional law?
- The president may remove federal judges at will
- Federal courts may declare acts of Congress unconstitutional Correct answer.
- States may nullify federal laws they consider unjust
- Congress may override Supreme Court decisions by majority vote
Explanation
Chief Justice John Marshall held that a law conflicting with the Constitution cannot be enforced by the courts, establishing judicial review. The decision made the judiciary the arbiter of constitutional meaning without giving courts any enforcement power of their own.
Question 47United States History
President Andrew Jackson's response to South Carolina's nullification of the tariffs of 1828 and 1832 rested on the argument that
- the Union is perpetual and no state may unilaterally void federal law Correct answer.
- states created the federal union and may therefore leave it
- the Supreme Court, not the president, should settle all tariff disputes
- tariffs are unconstitutional because they favor manufacturing states
Explanation
In his 1832 proclamation on nullification, Jackson insisted that the Constitution formed a permanent union of the people, not a league of sovereign states, so a single state could not annul a federal statute. He paired this with a threat of force in the Force Bill while supporting a compromise tariff.
Question 48United States History
Which development most directly prompted the United States to annex Texas in 1845?
- The collapse of the Second Bank of the United States
- The discovery of gold in California
- Fear that Great Britain would bring Texas into its sphere of influence Correct answer.
- A ruling by the Supreme Court upholding the annexation treaty
Explanation
President John Tyler pushed annexation through a joint resolution in 1845 partly because British diplomacy with the Republic of Texas raised fears of a rival power on the southwestern border. Annexation also fulfilled expansionist and proslavery political goals, but the British angle was the immediate catalyst.
Question 49United States History
The Compromise of 1850 addressed sectional conflict by
- banning slavery in all territory acquired from Mexico
- admitting California as a free state while allowing popular sovereignty in the Utah and New Mexico territories Correct answer.
- repealing the Fugitive Slave Act of 1793
- admitting Kansas and Nebraska as slave states
Explanation
The compromise admitted California as a free state, organized Utah and New Mexico without a slavery restriction so settlers could decide, and included a tougher fugitive slave law. It was a package of trade-offs rather than a single rule.
Question 50United States History
The Supreme Court's decision in Dred Scott v. Sandford (1857) intensified sectional tensions because it
- granted citizenship to free African Americans born in the United States
- required northern states to extradite escaped enslaved people
- declared that Congress could not prohibit slavery in the territories Correct answer.
- upheld the constitutionality of the Missouri Compromise
Explanation
Chief Justice Taney ruled that Congress lacked power to bar slavery from federal territory, which struck down the Missouri Compromise's restriction and threatened the Republican Party's core platform. The decision also denied that African Americans could be citizens, deepening northern outrage.