The National Archives include all documents and materials relating to the business of the U.S. federal government. Within the collections is the African American History Research page as well as online veterans and military records, which are searchable by race and geographic location, including county.
Within the National Archives Catalog (ARC) is the 1917 picture of Negro draftees in Lexington, KY. There is much more -- visit the National Archives website. The National Archives are located in College Park, MD.