Consists of documents of the Clarke family. Included are twenty deeds, seven wills, and five mortgages of various generations of Clarkes; papers relating to family members who died intestate; inventories of household goods, documents, and receipts concerning the estates of William Clarke (1734-1802), Matthew Clarke (died circa 1820), Caleb Hulfish (died circa 1860), and David B. Hill (died circa 1888); and a diary (1886-1900) kept by William H. Clarke (d. 1906). Also included are miscellaneous documents such as a receipt (1794) for use of the (Quaker) Friend's School at Stony Brook, a New York marriage contract (1735) between John Clarke and Sarah Field, and an indenture (1865) binding an apprentice to John H. Clarke.

Many of the documents refer to other local residents of the 18th and 19th centuries, including Robert Stockton, Cornelius Covenhoven, Samuel Oldden [Olden], Robert White, Abraham Schuyler, and Henry E. Hale.