CLEP Social Sciences and History cheat sheet

Columbian Exchange (after 1492): transfer of crops, livestock, and diseases between hemispheres; smallpox devastated Indigenous populations while maize and potatoes raised Eurasian food supply.

Constitutional compromises of 1787: Great Compromise created a bicameral Congress (population-based House, equal Senate); Three-Fifths Compromise counted enslaved persons at 3/5 for representation and direct taxation.

Civil War causation sequence: Kansas-Nebraska Act (1854, popular sovereignty) repealed the Missouri Compromise line, spurring the Republican Party; Lincoln's 1860 election triggered secession.

Reconstruction amendments: 13th abolished slavery (1865), 14th granted citizenship and equal protection (1868), 15th protected voting rights by race (1870).

Progressive Era reforms: 16th Amendment (income tax, 1913), 17th (direct Senate election, 1913), 18th (Prohibition, 1919), 19th (women's suffrage, 1920).

New Deal programs: Social Security Act (1935) created old-age pensions and unemployment insurance; the Wagner Act (1935) protected collective bargaining.

Cold War containment: Truman Doctrine (1947) and Marshall Plan (1948) aimed to block Soviet expansion in Europe; NATO formed 1949 as a collective-defense alliance.

Civil rights milestones: Brown v. Board (1954) struck school segregation; Civil Rights Act (1964) banned public-accommodation discrimination; Voting Rights Act (1965) authorized federal oversight of elections.

Separation of powers: legislative (Article I), executive (Article II), judicial (Article III); each branch checks the others, e.g., veto override by two-thirds of both chambers.

Federalism layers: enumerated (delegated) powers to Congress, reserved powers to states under the 10th Amendment, concurrent powers shared (taxation, courts).

Judicial review: Marbury v. Madison (1803) established courts' power to void laws conflicting with the Constitution; precedent follows stare decisis.

Bill of Rights application: originally limited to the federal government; the 14th Amendment's due-process clause selectively incorporated most protections against states.

Election mechanics: Electoral College has 538 votes (House seats + 2 senators + 3 for D.C.); 270 needed to win; state winner-take-all except Maine and Nebraska.

Legislative process: bill introduced, committee markup, floor vote, conference committee reconciles versions, presidential signature or veto; filibuster requires 60 votes to end in the Senate.

Types of powers: expressed, implied (necessary and proper clause), and inherent; executive orders carry force of law but can be overturned by statute or courts.

Public-opinion measurement: random sampling reduces bias; sampling error shrinks with larger samples; push polls and leading questions distort results.

Latitude measures north-south position (0-90 degrees); longitude measures east-west (0-180 degrees); one degree of latitude is roughly 111 km everywhere.

Climate controls: latitude, altitude, proximity to water, ocean currents, and prevailing winds; coastal areas have smaller temperature ranges than continental interiors.

Plate tectonics: divergent boundaries create rifts and mid-ocean ridges; convergent boundaries produce subduction, volcanoes, and mountain belts; transform boundaries cause strike-slip faults.

Population measures: arithmetic density = population / land area; physiological density = population / arable land; doubling time approximates 70 divided by annual growth rate percent.

Demographic transition stages: high birth and death rates, then death rates fall, then birth rates fall, ending with low rates and slow or negative growth.

Push-pull migration: push factors include conflict and unemployment; pull factors include jobs and services; intervening obstacles (borders, cost) modify flows.

Economic sectors: primary (extraction), secondary (manufacturing), tertiary (services), quaternary (information and research); development typically shifts employment toward tertiary and quaternary.

Urban models: concentric zone, sector, and multiple-nuclei models describe land-use patterns; bid-rent theory places high-value uses near the center.

GDP = C + I + G + (X - M); it counts final goods produced within a country's borders in a period, excluding intermediate goods and transfer payments.

Real vs. nominal values: real GDP adjusts for inflation using a price index; real interest rate approximately equals nominal rate minus inflation.

Supply and demand: a price above equilibrium creates surplus; below equilibrium creates shortage; a price ceiling below equilibrium causes persistent shortage.

Elasticity: demand is elastic when percentage quantity change exceeds percentage price change; necessities and goods with few substitutes tend to be inelastic.

Money multiplier = 1 / reserve requirement; central banks expand the money supply by buying bonds, lowering the discount rate, or lowering reserve requirements.

Fiscal policy: expansionary = higher government spending or lower taxes; contractionary = the reverse; automatic stabilizers include unemployment insurance and progressive taxes.

Comparative advantage: a country gains by specializing where its opportunity cost is lowest, even if it lacks an absolute advantage in every good.

Business cycle: expansion, peak, contraction (recession, often defined as two quarters of falling real GDP), and trough; unemployment rises during contractions.