The Salem Insurance Companies Records are comprised of papers generated from miscellaneous Salem insurance companies, insurance offices coordinated by individual insurance brokers, and the insurance activities of group underwriters. This collection provides an overview of the history of Salem's insurance business, from group underwriting businesses of the 1780s-1820s to the fully developed insurance companies of the 19th century. The collection has been divided into four series.

Series I. Insurance Companies includes papers of eight marine and fire insurance companies from 1800 to 1893. Of note are furniture inventories included with policy proposals of the Essex Mutual Fire Insurance Company and the correspondence of the Salem Marine Insurance Company (1800-ca. 1840) (a company which is not to be confused with the later firm (1856-1897) of the same name, see MSS 137). This correspondence, most of which is with company president Jacob Ashton, discusses the marine claims of the brig Traveller, ship Merry Quaker, Industry, Borneo, brig Hazard, and schooner Ruth. The legal papers of the Union Marine and Fire Insurance Company consist of three copies of an 1813 case brought by the company against William Woart for the theft of company funds.

Series II. Insurance Office Records, 1794-1824, contains volumes of policies and miscellaneous papers generated by insurance offices which were headed by individual insurance brokers. These brokers coordinated group underwriting activities through their offices.

Series III. Group Underwriters, 1779-1828, reflects the early insurance activities of a number of Salem's prominent citizens. Organized more loosely than insurance offices, group underwriters were made up of wealthy merchants who put up capital to insure the cargos and vessels of others. Among the men who appear most often as underwriters in the policy volumes are John Appleton, John Barr, Francis Cabot, N. Goodale, Benjamin Goodhue, Joseph Grafton, William Gray Jr., Isaac Needham, Josiah Orne, Willard Peele, Stephen Phillips, Aaron Waite, and Joshua Ward Jr.

Series IV. Miscellaneous Insurance Papers include insurance applications, indexes and shares of insured vessels, and miscellaneous papers.