Austerlitz was organized from parts of the towns of Hillsdale, Chatham, and Canaan, March 28, 1818. A little more than one-fifteenth of the present town was taken from Chatham, a little over one-eighth from Canaan, and a little less than five-sixths from Hillsdale. This area was first settled in 1757 under a deed from Mohican Indians to 75 settlers, who established the proprietorship of Spencers Town, there being 12 Spencer families in the group. The Mohicans and the settlers thought Spencers Town was in the colony of Massachusetts Bay, but New York's jurisdiction was established before the Revolution.
The new Town Hall is now open for business. Offices are located on the lower level. The upstairs remains closed to the public for now while construction continues in the court/meeting room.