The UMSL Digital Library is a repository for the various digital collections of the University of Missouri-St. Louis library system. This includes books, periodicals, and other circulating and reference works in the holdings of the Thomas Jefferson Library. Records from the University Archives and other campus departments may also be represented here or in MOspace, the UM system's institutional repository. Perhaps the largest use of this digital library is to provide access to archival materials from the collections of the St. Louis Mercantile Library, the oldest library west of the Mississippi River. The Mercantile itself is home to an art museum and two large special collections libraries: the Hermann T. Pott National Inland Waterways Library and the John W. Barriger III National Railroad Library.