Dundalk (dŭnˈdôlkˌ) [key], city (1990 pop. 65,800), Baltimore co., NE Md., a suburb of Baltimore, on the Patapsco River; inc. 1946. It has one of the world's largest steel plants and a nine-berth marine terminal, operated by the Maryland Port Authority. Factories there make electronic parts, auto bodies, and yachts. The first house built (1665) in the city was burned by the British after their march on Washington (1814) during the War of 1812. U.S. Fort Holabird is nearby.