The St. Louis Mercantile Library has broad holdings of particular interest to researchers of the history of St. Louis, Western Expansion, Western Art, railroads, and inland waterways.  Since its founding in 1846, the library has gained the holdings, traditions, and resources of St. Louis's oldest libraries, the St. Louis Library Company of 1821 and the Saint Louis Lyceum of 1838, who in turn benefited from many of the books and documents privately owned by St. Louisans going back to the city's founding. 

Now affiliated with the University of Missouri - St. Louis, the Mercantile's circulating books have merged into the university's catalog for use by students and library association members as well as the general public.  This has allowed the Mercantile to focus its efforts on developing its special collections.  Processed collections can be browsed from this website, and many have digital content such as finding aids or scanned images of documents available on their individual pages.

Collections are available for in person viewing during scheduled hours, but visitors must follow the posted reading room procedures.  Photography is allowed in the reading room under conditions stated in the library's rules concerning cameras.  Images may also be purchased, with discounts for members, according to the posted images price list.  All library materials are subject to copyright

The library staff welcome inquiries, but patrons are encouraged to take advantage of the Reference Assistance program available to them.  There are research guides which may also be useful.