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 Metropolitan Area. Founded in 1772, the town contains the B. & O. Railroad Museum’s branch at the Ellicott City Station, built in 1830 as the first terminus of the initial line. The downtown historic district is located in the valley of the small Tiber River, with its east end abutting the Patapsco River, which forms the Baltimore County line. The downtown area in the Patapsco Valley is often called “Historic Ellicott City” or “Old Ellicott City”, to distinguish it from the surrounding suburban unincorporated area that extends south to the other large unincorporated town in Howard County, Columbia, and west to West Friendship.
Ellicott City proper is served by Mount Hebron High School, Centennial High School, Wilde Lake High School, and Howard High School in the Howard County Public School System; Marriotts Ridge High School serves most of the rest of the CDP area Two of the system’s special schools, along with the central offices, also have Ellicott City addresses, though in fact they are on the northern edge of Columbia.