Period 1: 1491–1607

What this unit covers

The topics below follow the published US History course framework for Unit 1. This unit is worth 4–6% of the exam, so budget your time against that rather than against how long the unit takes to teach.

Lessons in this unit

• Native Societies Before Contact13 min · 3 objectivesExplain how environment shaped the diversity of Native American societies before European contact · Compare the social and economic organization of major culture regions · Connect the spread of maize agriculture to population growth and settlement patterns
• European Expansion & the Columbian Exchange14 min · 3 objectivesIdentify the motives and technologies driving European exploration after 1450 · Analyze the biological and economic consequences of the Columbian Exchange · Explain how the exchange transformed populations on both sides of the Atlantic
• The Spanish Empire & Cultural Encounters12 min · 3 objectivesDescribe the Spanish system of colonization, including the encomienda and casta systems · Explain how labor demands drove the shift toward African slavery · Evaluate competing European justifications and critiques of conquest

Every term in Unit 1

All 16 terms we publish for Period 1: 1491–1607, with definitions. Reading them through is the fastest way to find the ones you cannot define — then drill those in cram mode until you can produce them without the prompt.

Mercantilism

The belief that global wealth is fixed, so a nation grows rich by exporting more than it imports and holding colonies as sources of raw materials and captive markets.

Columbian Exchange

The transatlantic transfer of plants, animals, people and disease after 1492. Maize and potatoes drove European population growth; smallpox and measles killed up to 90% of Native populations.

Encomienda system

Spanish labor grant giving a colonist the right to demand tribute and work from Native people in a district, in exchange for nominal protection and Christianization. Coerced labor in all but name.

Casta system

Spanish colonial racial hierarchy — peninsulares, criollos, mestizos, mulattoes, Native peoples, Africans — which fixed legal and social privilege by ancestry.

Maize cultivation

Spread north from Mesoamerica and allowed permanent settlement and irrigation in the Southwest. The reason Pueblo societies were sedentary while Great Basin peoples were mobile.

Pueblo peoples

Southwestern societies who built permanent adobe settlements and irrigated maize agriculture in an arid environment — the CED's central Period 1 example of environment shaping society.

Great Plains nomadic societies

Peoples who followed buffalo herds and lived in portable dwellings because the Plains could not support farming with the technology available.

Iroquois Confederacy

Alliance of five (later six) Northeastern nations governed by a shared council — evidence that Native societies had complex political institutions before contact.

Pacific Northwest societies

Chinook and neighbors built permanent villages on abundant salmon and timber without agriculture, proving sedentary life did not require farming.

Bartolomé de Las Casas

Dominican friar who condemned Spanish treatment of Native peoples and argued for their humanity; his critiques fed the Valladolid debate and the "Black Legend".

Juan Ginés de Sepúlveda

Argued Native people were natural inferiors whose conquest was justified. Opposed Las Casas at Valladolid (1550–51), the era's central debate over Native humanity.

Requerimiento

Document read aloud in Spanish to Native peoples demanding submission to Crown and Church, which legally justified war if they refused. A ritual of legitimation, not communication.

Joint-stock company

Investors pooled capital and shared risk and profit. Financed English colonization without Crown money — why English colonies began as commercial ventures.

Treaty of Tordesillas (1494)

Papal-brokered line dividing new lands between Spain and Portugal, giving Portugal Brazil and Spain most of the Americas.

Mission system

Spanish religious settlements aimed at converting and controlling Native populations, combining evangelism with labor extraction and cultural suppression.

Mestizo

A person of mixed European and Native descent. Their number in Spanish America, versus their rarity in English colonies, reflects sharply different settlement patterns.

What examiners penalize here

• On the exam, resist writing about Native Americans as one uniform group. The CED wants you to argue that **environmental variation produced social variation**. Naming a specific region and its adaptation (irrigation, bison hunting, salmon fishing) earns the point.
• When a prompt asks about the *shift* to African slavery, argue causation explicitly: Native depopulation + rising profits + disease-resistant, trade-accessible African labor. Naming all three links reads as sophisticated analysis, not just description.

Practice US History

Our practice bank is drawn from across the whole course rather than filtered to one unit, which is closer to how the exam asks anyway — it will not tell you which unit a question is testing.

Questions about this unit

All 9 units of AP United States History

1. Unit 1 · Period 1: 1491–1607
2. Unit 2 · Period 2: 1607–1754
3. Unit 3 · Period 3: 1754–1800
4. Unit 4 · Period 4: 1800–1848
5. Unit 5 · Period 5: 1844–1877
6. Unit 6 · Period 6: 1865–1898
7. Unit 7 · Period 7: 1890–1945
8. Unit 8 · Period 8: 1945–1980
9. Unit 9 · Period 9: 1980–Present