The Chicago Public Library opened its doors on January 1, 1873. From the beginning, the Library has acquired books and periodicals about Chicago. Today the library also actively collects manuscripts, photographs, maps, and ephemera about the city.

Under CPL's Archives and Special Collections (ASC) division, highlights include an extensive collection chronicling the development of Chicago neighborhoods; the Vivian G. Harsh Research Collection, the largest collection of African American history and literature in the Midwest; the archives of Harold Washington, the first African American mayor of Chicago; papers and photographs from the 1893 World’s Columbian Exposition and the 1933-1934 Century of Progress International Exposition; the archives of Chicago theaters, which range from small store fronts to large auditoriums; letters and diaries of local soldiers in the Civil War; the archives of the Chicago Public Library; and the Municipal Reference Collection, the city’s most comprehensive holding of local government material.