When England established colonial counties in the Province of New York in 1683, the territory of present Oneida County was included in a very large, mostly undeveloped Albany County. This county included the northern part of present-day New York State as well as all of the present state of Vermont and, in theory, extended westward to the Pacific Ocean. This county was reduced in size on July 3, 1766 to create Cumberland County, and further on March 16, 1770 by the creation of Gloucester County, both containing territory now in Vermont.