Chicago Historical Society: Devoted to collecting, interpreting, and presenting the rich multicultural history of Chicago and Illinois.
Illinois Central Railroad Historical Society: Dedicated to the preservation of historical and educational information about the Illinois Central Railroad and the many predecessor railroads that have been part of the Illinois Central System.
Illinois Heritage Association: Perpetuating the history and heritage of Illinois by providing professional services to educational institutions, local government bodies and nonprofit agencies.
Illinois State Historical Society: Promoting a deeper understanding of and appreciation for Illinois history.
Society Hill: Illinois Societies: Directory of Illinois historical societies. Includes contact information and links.