Ellicott City is an
unincorporated community and
census-designated place, along with being the
county seat of local government in
Howard County, Maryland,
United States. It is part of the
Baltimore–Washington Metropolitan Area. The population was 65,834 at the
U.S. Decennial Census of 2010. It is the
county seat of Howard County. Founded in 1772, the town contains the
B. & O. Railroad Museum's branch at the
Ellicott City Station, built in 1830, and the first terminus of the initial line. The downtown historic district is located in the valley of the upper Western Branch of the
Patapsco River. As of the
2000 U.S. Census, Ellicott City surpassed
Towson, Maryland (
county seat of neighboring
Baltimore County) for the first time, as the largest unincorporated
county seat in the country.