The Mary Ball Washington Museum and Library in Lancaster, Virginia, preserves the history of Lancaster County and the Northern Neck through a museum, archive, and research library established in 1958. Named for Mary Ball Washington, a Lancaster County native and mother of George Washington, it holds about 10,000 books, periodicals, manuscripts, and genealogical resources dating to 1651. Together, its collections trace roughly 350 years of local and regional history, including nearby Middlesex and Essex counties. Part of a five-building complex in the Lancaster Courthouse Historic District, it also includes several historic structures and serves the public through exhibits, tours, educational programs, and family-history research.