How do David Walker and Alexander Crummell respond to the idea of colonization?

Walker, a free black man living in the pre–Civil War United States, strongly opposed colonization. Many people thought the "problem" of black people in the United States could be solved by sending black people living in the United States back to Africa. Walker disagreed and became one of the founders of the Massachusetts General Colored Association, a group which fought against deporting black people to other parts of the world, such as Liberia. Instead, he wanted to end slavery and discrimination in America. He died, however, in 1830, decades before the dream of abolition came to fruition.

Like Walker, Crummel, also black, initially opposed colonization of Africa by US black people. However, he later changed his mind. After he traveled to Liberia as an Episcopal missionary in 1853, he came to strongly support colonization of Africa by US black people. He thought American black people had a special responsibility to bring western civilization and the Christian religion to the African continent.