the first subway in north america was in boston. building started in 1895 and the first section was opened in 1897. the tunnels for this subway are still used by the green line of the massachusetts bay transportation authority (mbta), who has since built some other subways. in 1904, the new york city subway opened, serving new york city. it quickly grew and soon became one of the largest in the world. it still has the most stations of any rapid transit system, with over 400 of them. several more cities in the united states and canada built their own subways, such as philadelphia (operated by septa); los angeles (operated by metro); montreal metro in montreal, toronto subway in toronto and vancouver skytrain in vancouver, canada.