Martinsburg is a city in and the county seat of Berkeley County, West Virginia, United States, in the tip of the state's Eastern Panhandle region in the lower Shenandoah Valley. Its population was 17,454 in the 2019 census estimate, making it the largest city in the Eastern Panhandle and the eighth-largest municipality in the state. Martinsburg is part of the Hagerstown-Martinsburg, MD-WV Metropolitan Statistical Area.

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