From around 1800, in the United States, people opposed to slavery were planning ways to achieve freedom of more slaves and, ultimately, to abolish the institution. At the same time, slaveholders in the South opposed having free blacks in their states, as they believed the free people threatened the stability of their slave societies. While they were gradually freed in the North, the former slaves and other free blacks suffered considerable social and legal discrimination. Like Southern states, some Northern states and territories (Illinois was one) severely restricted or prohibited altogether entry by free people of color.