The Library has extensive materials related to St. Louis history, Missouri history, the history of the American West, genealogy and family history, neighborhood histories, urban history, Native American ethnology, letters, diaries, and works by St. Louis authors. The Library houses more than 90,000 cataloged volumes, pamphlets, and periodicals, rare 17th- and 18th-century maps of North America, more than 5,000 pieces of sheet music, 500 bound volumes of published music, and theater programs dating from the early 19th century.
The Archival Collection consists of more than 2,850 separate collections, with such rare items as the elk-skin journal of William Clark's 1804 expedition of the West and papers of Thomas Jefferson.
The Photographs and Prints Collection consists of more than 600,000 images, with more than 600 daguerreotypes made by Thomas Easterly between 1840 and 1880 that document the development of St. Louis and its early residents.
The Broadcast Media Collection contains more than 10,000 videotapes and 5,000 reels of film that document early St. Louis radio and television.
The Objects Collection contains more than 160,000 items that include more than 10,000 items of historic clothing and textiles.