Unit 4: Transoceanic Interconnections (1450–1750)
AP World History: 58 practice questions with detailed explanations.
Unit Study Guide
Executive Summary
European maritime exploration stitched the hemispheres together — the Columbian Exchange, new maritime empires, and a transatlantic slave trade transformed the world.
Exploration
Motivated by God, gold, and glory — and enabled by caravels, astrolabes, and lateen sails — Portugal rounded Africa (Vasco da Gama reached India, 1498) and Spain crossed the Atlantic (Columbus, 1492). The Treaty of Tordesillas (1494) split the non-European world between them.
Maritime empires
Spain built a silver empire in the Americas with encomiendas and haciendas; Portugal created a trading-post empire (Goa, Malacca, Macau). The Dutch and English followed with joint-stock companies (VOC, EIC). Mercantilism and joint-stock finance funded it all.
The Columbian Exchange
Crops (maize, potatoes), animals (horses, cattle), and diseases (smallpox, measles) crossed both ways. American food crops fed Eurasian population growth; Old World diseases devastated American populations.
The Atlantic system
Sugar plantations in Brazil and the Caribbean ran on enslaved African labor — the middle passage moved over 12 million people. Cash crops, silver (Potosi), and coerced labor (mita, chattel slavery) defined the Atlantic economy.
Exam traps
The Columbian Exchange was TWO-way — don't one-directionalize it. Disease, not weapons, conquered the Americas. Portugal's empire was trading posts, Spain's was land and silver mines. The slave trade was a system of extreme coercion, not "migration."