State Historical Society of Missouri
From the CMS website: Citizens, officials and students interested in Missouri history, biography and genealogy find in the society library unsurpassed reference collections. The library of books, pamphlets and official state publications total more than 460,000 items. There are also more than 500,000 manuscript items and 800 reels of microfilmed manuscripts, more than 150,000 state archival records, and more than 2,900 maps.
