Answer:
European sailors acted in that way because they considered African Americans to be property that could be bought, sold, flogged, mistreated, and even killed. In other words, they did not think that African Americans were people who had rights, but a tool, or a merchandise, almost like a plough or a net.
These views prompted the development of a massive slave trade between Europe, Africa, and the Americas. The slaves were taken from the African Coasts by European sailors, merchants, and slave-traders (often sold by African leaders), and they took these enslaved Africans on ships to the Americas, were they would work in cash crop plantations.
Most of the slaves were taken to Brazil and the Caribbean, and a considerable minority were taken to the Southeastern United States, were a slave economy developed in the Tidewater region, and in the Deep South, were cash crops, profitable, but very intensive in labor, were cultivated (rice, tobacco, and mainly cotton).
