Series III. Financial Records and Correspondence includes all business records created by or for Bates & Co., including financial accounts, business correspondence not directly connected to a single ship, building and wharf leases, insurance papers, trade memos, vessel lists, trade circulars, textiles, and account books. General financial materials are arranged by subject or format; accounts and correspondence to or from specific individuals or companies are arranged alphabetically by name. All materials are arranged chronologically within each individual folder.

The correspondence and accounts with Bates & Co.'s business associates are a particularly rich element of the series. A striking highlight is the correspondence between brothers Edward C. Bates and John D. Bates during the former's work as an agent for the company; Edward Bates wrote extensively from Cuba and Europe during the early 1830s, and his letters provide minute details of the sugar trade in the early years of the company after Nathan Bridge's death. John D. Bates, Jr.'s letters with his father in the early 1860s lend insight into the company's activities leading up to John Bates' death in 1863, and their correspondence reveals the intersection between their professional and personal lives.

Other business associates with strong representation in the series are Augustine Heard & Co., the Brothers Cramer, the Brothers Nottebohm, George Knight, Moody & Telfair Insurance Co., James Oakes, and F.D. Williams of Williams & Co. Correspondence from F.D. Williams includes mentions of human trafficking from China to Cuba in the 1860s; in addition to the materials related to the Carrington in Series II, he also mentions human trafficking in 1863 aboard the ship Don Quixote, the Fanny Fern, the Julia G. Tyler, and the Sarah Chase. Please note that language and content in these materials may be disturbing to users.