New York Slavery Records Index – Records of Enslaved Persons and Slave Holders in New York from 1525 through the Civil War (John Jay College)
Dutchess African Heritage Studies: Walter M. Patrice Online Library (Dutchess County Historical Society)
New York Heritage Digital Collections – search for “slave register”
Free newspaper websites:
a. New York State Historic Newspapers
b. Old Fulton Postcards
c. Hudson River Valley Historical Newspapers