Ossining Town Hall is located at 16 Croton Avenue, Ossining NY 10562; phone: 914-762-6000.
The town was purchased in 1685 by Frederick Philipse from the Sint Sinck Indians who were part of the Wappinger Confederacy. The land area was part of the Manor of Philipsburg. As the last lord of the manor, Colonel Frederick Philipse, was a British Loyalist during the Revolutionary War, the manor was confiscated by the State in 1779. Many of the former tenants of the Manor bought their farms from the State.
The township of Ossinsing was created from the Town of Mount Pleasant in 1845, and was named on the advice of an eminent Indian authority. Ossinsing was an alternative form of "Sing Sing." The name was shortened to Ossining in 1846 as to make it easier for people to pronounce.