Clarksburg is a city in and the county seat of Harrison County, West Virginia, United States, in the north-central region of the state. The population of the city was 16,039 at the 2020 census, making it the tenth-most populous city in West Virginia. It is the principal city of the Clarksburg micropolitan area, which had a population of 90,434 in 2020. Clarksburg was named National Small City of the Year in 2011 by the National League of Cities.

The Northwestern Turnpike is a historic road in West Virginia, important for being historically one of the major roads crossing the Appalachians, financed by the Virginia Board of Public Works in the 1830s. In modern times, west of Winchester, Virginia, U.S. Route 50 follows the path of the Northwestern Turnpike into West Virginia, whose major Corridor D project follows the western section of the original Northwestern Turnpike.