Lancaster’s Thayer Memorial Library has a multitude of special collections in the Constance V. R. Dexter Special Collections Room, including the John C. L. Clark Botanical Collection, local manuscripts, and rare books. The library’s Historical Museum, which was established in 1863, is a permanent exhibit of Civil War memorabilia, pre-historic tools, 19th-century physician’s instruments, and other artifacts relating to the town’s history. Access to both the Special Collections Room and the Historical Museum must be arranged with the library in advance.

Thayer Memorial Library also has an art collection that is available for check-out.