Charlotte County in the colonial Province of New York was created in 1772 from Albany County. In 1784 the county name was changed to its current name, Washington County, in order to honor George Washington. In 1799 Clinton County was created from part of Washington County. Clinton County itself was partitioned to form other upstate counties. The Town of Cambridge was transferred in 1791 from Albany County to Washington County.

See also:

• List of extinct U.S. counties
• List of New York counties