The document outlines the evolution and growth of the transatlantic slave trade between Africa and the Americas from the 16th to 19th centuries. It notes that while slavery has ancient origins, the scale increased with European demand for labor in their new colonies. Over 9.5 million African slaves were transported across the Atlantic during this period, primarily to work brutal conditions on plantations in the West Indies and American South growing cash crops like sugar, tobacco, and coffee. The Middle Passage during this transportation resulted in horrific conditions for slaves as they were forcibly held in cramped ship hulls, often enduring beatings, disease, and many deaths along the voyage.