The Samuel Roundy papers document the activities of this Marblehead, Massachusetts, ship captain. It contains shipping papers, account books, and some personal papers and is organized into three series.

Series I. Shipping Papers consists of bills of lading, passports, protests, a chart of the Atlantic Ocean, and a song written by one of the crew on the ship Delphos talking about the treatment by the officers. Other vessels mentioned in folder 4 are the Circumnavigator (Ship), Polly (Ship), Triton (Schooner), and Eliza (Bark).

Series II. Account Books contains nine volumes of different kinds of account books, mainly for the schooners Industry and Edward and Richard, but including the brig Hope and the schooner Regulator as well as personal journals and accounts. It also includes a logbook for the brig Orient (John Girdler was master) which traveled from Marblehead to India beginning July 24, 1819. The log ends in 1820. Many of the volumes were used for multiple accounts and some entries are dated after Samuel's death.

Series III. Personal and Family Papers consists of receipts (business and personal), a letter to Deborah Roundy, two letters from Samuel to Deborah where he addresses her as "Honoured Mother", four deeds to Deborah Roundy and one to John Cloutman from Dudley Woodbridge, and some genealogy of the Charles Roundy family.