The Providence and Worcester Railroad (reporting mark PW) is a Class II railroad operating in Rhode Island, Massachusetts, and Connecticut, as well as New York via trackage rights. The company was founded in 1844 to build a railroad between Providence, Rhode Island, and Worcester, Massachusetts, and ran its first trains in 1847. A successful railroad, the P&W subsequently expanded with a branch to East Providence, Rhode Island, and for a time leased two small Massachusetts railroads. Originally operating on a single track, its busy mainline was double-tracked beginning in 1853, following a fatal collision that year in Valley Falls, Rhode Island.