Jefferson County was formed from Berkeley County on October 26, 1801 by an act of the Virginia General Assembly. It was named for Thomas Jefferson, then president of the United States. Located in the eastern panhandle of West Virginia, Jefferson is the easternmost county in the state. It is bounded by the Potomac River and Washington County, Maryland to the north, the Blue Ridge Mountains and Loudoun County, Virginia, to the east, Clarke County, Virginia, to the south, and Opequon Creek and Berkeley County, West Virginia, to the west.