Air Force Historical Research Agency
The Air Force Historical Research Agency maintains a depository for United States Air Force historical documents. The documents collection was originally located in Washington D.C. after World War II and is presently at Maxwell Air Force Base near Montgomery, AL.
The depository has the world's largest collection of documents on U.S. military aviation, with information on Kentucky African Americans, including the formation of the 477th Bombardment Group [Roy Chappell was a member] described in The Freeman Field Mutiny: a study in Leadership [.pdf].
Visit the Air Force Historical Research Agency website for much more information.