Final answer:
Throughout the 19th and 20th centuries, African people were predominantly engaged in agricultural labor, both in African societies disrupted by the slave trade and in the Americas as enslaved individuals and later as agricultural workers and manual laborers.
Step-by-step explanation:
The most common occupation of African people during the 19th and 20th centuries was primarily in agriculture, due to the extensive demand for labor to work in the fields of various cash crops like sugar, cotton, and tobacco in the colonies. The transatlantic slave trade had a devastating impact on African societies by forcibly removing a significant portion of the population, particularly the young and able-bodied, which led to major shifts in traditional economic roles and structures. In the aftermath of slavery and throughout the 20th century, many Africans, and later African Americans, were engaged in manual labor both in the rural contexts of plantation work and in urban industrial settings. This occupation was sustained even during the Great Migration when African Americans moved northward, seeking better opportunities but often found themselves in menial employment.