The United States took the land from Spain in 1797, and Andrew Jackson implemented the Indian Removal Act that facilitated the expulsion of the Cherokee from the area, making it available to white settlers. The city was established in 1819. Until the American Civil War, Memphis was a hub of cotton and slave trade. Brutal riots of angry whites against black people took place in 1866, in which 46 African Americans were killed. Yellow fever struck the city in the 1870s, killing a lot of people. The city recovered, and its population more than doubled. 