The St. Louis Mercantile Library represents their work through collections that have a varied focus on Westward Expansion, American rail river transportation, the history, development, and growth of the St. Louis region, and a wide range of subjects about the humanities. The St. Louis Mercantile Library houses over 250,000 books with over 4000 individual collections with archival materials beyond millions including over 100 historic newspaper titles, presidential letters, travel diaries and Civil War era letters, fur trade records, and the newspaper and printing morgue of the St. Louis Globe-Democrat. The St. Louis Mercantile Library’s mission is to exist as the oldest library West of the Mississippi River and honor its established civil leaders to be an “active community asset” and memorialize heritage while maintaining a readily available space for scholars to explore. The archive was founded in 1846 by civic leaders and philanthropists seeking to have a library in the early cultivations of St. Louis. To understand the context of the documents you encounter in the archives you might need to have prior knowledge about other information regarding the concentrated collections within the library such as the West Ward Expansion, American rail river transportation, as well as information about the St. Louis region. This prior knowledge will provide a contextual understanding that may not be as clear within the text. The archive serves many generations of Missourians, members of the library, as well as scholars who are interested in the collections within the library. The St. Louis Mercantile Library serves its members not only with unlimited access to millions of books but also with other benefits. These benefits include special lectures, openings of special exhibitions of the collections, receptions, informal talks, and discounts on library services and publications.