Account books were maintained by individuals and business as a way to keep track of financial transactions. This collection includes thirty-eight account books from twenty-five different businesses and individuals in the Delaware, Maryland, and Pennsylvania area, with one additional account book from San Francisco County, California.

By the beginning of the nineteenth century, Pennsylvania was already a leader in the coal, iron, steel, railroad, and petroleum industries. As the manufacturing industries grew in the cities, so did the small businesses of craftsman and artisans that populated the surrounding areas selling their goods. These merchants played an important role in trade, community relationships, and the economy.  This is an artificial collection of account books, cash ledgers, and receipt books of nineteenth-century merchants of various industries in Pennsylvania. Minimal correspondence is included as well as a poem.  Mineral, iron and leather industries are represented as well as organ building which includes two treatises written in German.