The Oklahoma Department of Libraries is the official library of Oklahoma. Its history as a legal reference library for the executive, legislative, and judicial branches of government began with the establishment of the Territorial Library in the 1890s, which became the State Library in 1907. ODL houses the Oklahoma Center for the Book, an affiliate of the National Center for the Book in the Library of Congress. The OCB’s mission is to promote Oklahoma authors, books about our state, and reading for pleasure by all age groups.