Are black Americans descended from Africans?

Of course, the ancestors of black Americans all came from Africa, and there are many pure blacks in the United States. Although there are many hybrids, they are all black descendants from different African countries, and their descendants are pure black. There are no blacks in America, only Indians. Because of/kloc-the "black triangle trade" that started in the 6th century, that is, the slave trade. European slave traders set out from their own countries and loaded salt, cloth, rum and so on. And became slaves in Africa, crossed the Atlantic along the so-called "central route" and returned to America in exchange for sugar, tobacco and rice. In western Europe, near the Gulf of Guinea in Africa and between the West Indies in America, the route is roughly triangular. Because the trafficked person is black, it is also called "black triangle transaction". It lasted for 400 years.

Triangle trade sent African blacks to America for labor because Columbus discovered the New World and for colonial rule. They are strong and tall because of different geographical environments and can bear hardships. America is the first power, and they drink milk and eat meat all day. Do you think it can be strong?

Thank you for your reference!