Monongalia County, Virginia

Located in the Western District of Virginia

Monongalia County, Virginia

Named for the Monongahela River, Monongalia County was formed in 1776 from the District of West Augusta in Augusta County, Virginia. A large piece of southern Monongalia was carved out to form Harrison County in 1784. The eastern half of Monongalia County became Preston County in 1818. In 1842, Monongalia County lost more of its southern lands to form Marion County. In 1845, Preston County gained more land from Monongalia. The northern parts of Monongalia County were split off when the Mason-Dixon Line made the boundary between Virginia and Pennsylvania official.