When was slavery a major source of labor?

Slavery was a major source of labor from ancient times through the 19th century. In particular, it played a crucial role in the economies of the Americas during the transatlantic slave trade, which peaked between the 16th and 19th centuries. Enslaved people were primarily used in agriculture, particularly in the cultivation of cash crops like sugar, tobacco, and cotton. The institution of slavery began to decline in the 19th century, leading to its eventual abolition in many parts of the world.