Which company operated New York City’s original IRT subway system when it opened in 1904?

New York City’s original IRT subway system was operated by the Interborough Rapid Transit Company.

The IRT opened the city’s first subway line in October 1904, running between City Hall in Lower Manhattan and 145th Street in Harlem. The private company had received a franchise from New York City to build and operate the line.

The IRT used numbered routes and narrower cars than the later BMT and IND systems. This distinction remains visible today: numbered services generally belong to the former IRT Division, while lettered services mainly descend from the BMT and IND networks.

The Interborough Rapid Transit Company later became part of the city’s unified subway system. A common mix-up is confusing the IRT with the Independent Subway System, which was created later by the city and used lettered routes.