Answer Key: The Columbian Exchange

Full credit for any reasonable notice + prediction. Notice examples: "he focuses on trade goods (cotton, parrots, spears)," "he notices the people do not have swords/arms," "he pays attention to what he can trade for," "he notes marks of wounds." Predict examples: any crop, animal, person, or disease that could cross the ocean — "corn/potatoes," "horses/cattle," "people," "germs/disease." Accept any on-topic prediction — warm-up graded for effort.

Accept any reasonable idea in the student's own words: new foods spread so diets change; more food can support more people; peoples move (or are forced to move) onto new lands; new animals change farming and travel; new diseases spread. More than one answer is defensible.

From the Americas (any two): maize (corn), potatoes, tomatoes, cassava, cacao.
To the Americas (any two): wheat, sugarcane, coffee, horses, cattle, pigs, sheep, chickens — and, as the diagram also shows, diseases (smallpox, measles) and enslaved people carried by force from Africa. Accept any two correctly-directed items on each side. If a student lists disease or enslaved people as moving to the Americas, that is correct per the diagram.

Creator: attributed to the commander of the 1492 expedition (the voyage's journal). Accept "the explorer / expedition leader" or "the person keeping the voyage journal."
Date: 1492.
Type of source: a primary source that is public domain (a voyage journal, later published, here in translation). Full credit if identified as primary.
Purpose & point of view: written by a European explorer reporting to his sponsors, so it emphasizes trade goods and what the newcomers could gain, and it describes the Indigenous people from an outsider's, one-sided vantage point (noting they lack swords, could be traded with, etc.). Accept any clear one-sentence note that the creator is a European explorer whose purpose/perspective shapes what he emphasizes or leaves out. Good teaching point: a source can be genuine and still one-sided.

Causes (any two): sustained ocean voyages across the Atlantic connecting separated continents; European search for trade, wealth, and land; the building of colonies; ships carrying people back and forth.
Effects (any two): new crops/foods spread worldwide (maize, potatoes) and later helped populations rise; new animals (horses, cattle) reshaped farming, travel, and warfare; catastrophic loss of Indigenous life from new diseases (smallpox, measles); forced migration of enslaved Africans to plantations; changed economies (plantation agriculture, new trade goods).
Any two valid causes and two valid effects earn full credit. Watch for students placing a cause (e.g., "ocean voyages") in the effects column.

Model: "European ocean voyages after 1492 (cause) connected the Americas to the Old World, so ships carried the potato from the Americas to Europe (the exchange). In Ireland and northern Europe, the potato became a dependable, calorie-rich food, which over time helped the population grow (effect on population/agriculture)." Another valid model traces disease: "Ships also carried smallpox to the Americas, where Indigenous peoples had no immunity, causing catastrophic loss of life (effect on population and societies)." Award credit for a valid cause, a plausible link to the exchange, and a named effect on population, agriculture, economies, or societies in a specific place. See rubric below.

Corroborate. Both describe crops and animals spreading in both directions. Source A says maize, potatoes, and cacao spread from the Americas while wheat, sugarcane, horses, and cattle came to the Americas; Source B gives the on-the-ground picture (maize and cassava in West African fields, the potato in Ireland/northern Europe, Old-World cattle and horses grazing American lands, sugarcane on plantations). B illustrates and supports A. Reject "contradict": the two do not disagree. Explanation must cite one detail from each source.

a) F — checkable in Source A (potatoes and maize spread from the Americas).
b) I — a reasoned "probably" conclusion linking new crops to population growth.
c) O — a personal judgment ("most interesting event ever"); cannot be proven.
d) F — checkable in Source A (smallpox spread among peoples without prior immunity).
Fact = checkable; interpretation = reasoned from facts (often "probably/because"); opinion = personal belief or ranking.

Correct: B (No). Source A describes the exchange of crops and animals (horses, cattle, pigs), people (including enslaved Africans carried by force), and disease (smallpox, measles) — not crops alone. Reject A (Source A does not limit the exchange to crops) and C (crops such as maize and potatoes are named). Explanation must cite one such non-crop detail from Source A.

From the Americas → Old World (any one): maize, potatoes, tomatoes, cassava, cacao. Toward the Americas (any one): wheat, sugarcane, coffee, horses, cattle, pigs — or disease (smallpox, measles), or enslaved people from Africa.
Why sorting by direction helps: it makes visible that different items traveled different ways, showing the exchange was two-way (both to and from the Americas), not a one-way transfer. Accept any clear one-sentence version of that idea.

Open argument — no single correct effect. A strong response names one effect (population, agriculture, or societies), backs it with two accurate pieces of evidence, and reasons clearly and respectfully.
Sample (population): "The most significant effect was on population. Evidence: Source A says new diseases such as smallpox caused catastrophic loss of Indigenous life; it also says calorie-rich American crops later helped Old-World populations rise. Reasoning: because the exchange both devastated one population and helped others grow, it reshaped who lived where across whole continents."
Sample (agriculture): could cite Source A/B on maize and potatoes spreading and Old-World animals grazing American lands. Sample (societies): could cite the forced migration of enslaved Africans and plantation labor plus horses reshaping Plains peoples' lives.
Defensible alternates: any of the three effects is acceptable if supported by two on-topic pieces of evidence and sound reasoning. Do not reward a claim that names a cause (e.g., "ocean voyages") as an "effect," or that uses no packet evidence. Deduct if human-cost facts are treated flippantly or inaccurately.
[BLOCK] extended writing: full block credit requires (1) a second, distinct source or diagram element used as evidence, and (2) a genuine counter-consideration — naming why another effect could be judged most significant — followed by a reasoned defense or revision of the original claim.

Articulate: accept any accurate plain-language definition (e.g., "the Columbian Exchange was the two-way movement of crops, animals, people, and disease between the Americas and the rest of the world after 1492").
Connect: the cited items must actually be a cause and an effect — e.g., cause: ocean voyages / the search for trade and land / building colonies; effect: potatoes reaching Europe, horses reaching the Americas, disease killing Indigenous peoples, or the forced migration of enslaved Africans. Grade whether the pairing is correctly labeled.
Extend: any reasonable modern food tied to the exchange (potatoes, tomatoes, corn, chocolate/cacao, coffee, chili peppers, etc.) with a sensible reason. More than one answer is defensible; grade the reasoning.

Accept any defensible pairing supported by a detail: e.g., spread of disease → the Americas (smallpox/measles caused catastrophic Indigenous loss); new foods → Europe/Africa/Asia (potatoes and maize helped populations grow); forced migration → Africa and the Americas (enslaved Africans carried to American plantations); new animals → the Americas (horses reshaped Plains peoples' lives). Grade the reasoning and the use of a source/diagram detail, not the specific choice. Reward respectful, factual handling of the human-cost effects.