1. What contradiction does the system of slavery in the Americas highlight, according to the author? (Columbia exchange)

Christopher Columbus introduced horses, sugar plants, and disease to the New World, while facilitating the introduction of New World commodities like sugar, tobacco, chocolate, and potatoes to the Old World. The process by which commodities, people, and diseases crossed the Atlantic is known as the Columbian Exchange.

Explanation:

hello there the answer is a

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abraham lincoln  (february 12, 1809  – april 15, 1865) was an american statesman, politician, and lawyer who served as the 16th  president of the united states  from 1861 until  his assassination  in april 1865. lincoln led the nation through the  american civil war, its bloodiest war and its greatest moral, constitutional, and political crisis.[2][3]  he preserved the  union,  abolished slavery, strengthened the  federal government, and modernized  the u.s. economy.