Randolph County was formed from Harrison in 1787 and named for Edmund Jennings Randolph, a Virginia statesman and soldier. It is the largest county in the state. During the War between the states, Federal dominance of Tygart's Valley largely determined control of West Virginia. Tucker County was formed in 1856 from Randolph and named for Henry St. George Tucker, a Virginia statesman and jurist. The county contains the Fairfax Stone, which marks the boundary of the vast Fairfax estate, as well as Blackwater Falls and Canaan Valley.