Tremont Street Subway (Park Street) as the first U.S. subway

The Tremont Street Subway, with Park Street as one of its original stations adjacent to Boston Common, opened in 1897 and is generally recognized as the oldest subway tunnel in the United States. The tunnel was built to alleviate downtown streetcar congestion and originally served electric streetcars; Park Street Station remains an active transit hub. Some popular assumptions credit other cities with the first U.S. subway, but Boston's Tremont Street Subway predates New York City's first underground line.