Okiedoke links to a post by Sister Scorpion about black history in Oklahoma, including the freedmen -- black slaves of Oklahoma's Indian tribes who were freed after the Civil War and granted tribal membership. These freedmen founded a number of towns in Indian Territory, mainly in Creek and Seminole lands. They were joined by blacks who came to participate in the land runs that opened Oklahoma Territory. There was even hope of making Oklahoma a black state -- a place where African-Americans could enjoy self-determination and freedom from official and semi-official persecution. (It's sadly ironic that the first law passed by the Oklahoma state legislature was a "Jim Crow" law.)
Sister Scorpion's post includes a lot of links on Oklahoma black history as well as links related to Martin Luther King, Jr.