The papers include mostly business correspondence and financial records, including accounts with St. Anne’s Catholic Church (Detroit, Michigan) in 1770, taxes, and accounts relating to the administration of the estates Joseph Campau, administered by Theodore J. and Denys (Denis) J. Campau, and Nic(h)olas Campau, administered by Louis, Joseph, and Barnabas Campau. Other materials include wills, inventories, baptismal certificates, deeds, and a copy of the Campau genealogy. Some of the business correspondence is related to his sons’, Jacques, Nicolas, and Louis, business or financial interests. There is also a document concerning the capitulation of Detroit, 1812. Materials are written mostly in French up to 1849, and, afterwards, in English.