Clarksburg, city, seat of Harrison County, northern West Virginia, on the West Fork of the Monongahela River; incorporated as a city 1921. The city is a commercial, manufacturing, and shipping center for an area producing coal, petroleum, natural gas, and livestock. Glass and glass products are manufactured. A junior college is here. The community, settled in 1765, is named for the explorer George Rogers Clark. Clarksburg is the birthplace of the Confederate general Stonewall Jackson and served as a Union supply base during the American Civil War. Population 22,371 (1980); 18,059 (1990); 16,743 (2000).