The Amagansett Historical Association was founded in 1964, when the historic site was planned to become a supermarket and parking lot. The Miss Amelia Cottage, built in 1725, has been preserved as a museum demonstrating how Amagansett people lived from the earliest Colonial times through to the early 1900s.

The Roy K. Lester Carriage Museum is housed in an 1850 barn and the post-and-beam Richard S. Jackson Carriage House. The collection is focused on buggies and carriages that were built or used locally.

The Phebe Edwards Mulford House contains the Carleton Kelsey Archive of historical photographs.