The Mamaroneck Historical Society was first established in 1937 as the Old Town of Mamaroneck Historical Society. The Society remained active until 1954. The Society was re-established with its current name under a charter with the Board of Regents of the New York State Education Department in 1976.
The Society's mission is "to preserve local historical landmarks and public records; to encourage the study of local history and stimulate historical scholarship; to assemble genealogies of old families; to collect, assemble and provide for the display of historical objects and data and to inculcate reverence and respect for contributions of the past to the present."
The Society is a tax-exempt 501(c)(3) organization.