the general roca railway (fcgr) (native name: ferrocarril general roca) is a broad gauge railway in argentina which runs from constitución station in buenos aires to the south of the country through the provinces of buenos aires, la pampa, neuquén and río negro. it was also one of the six state-owned argentine railway divisions formed after president juan perón's nationalisation of the railway network in 1948, being named after former president julio argentino roca. the six companies were managed by ferrocarriles argentinos which was later broken up during the process of railway privatisation beginning in 1991 during carlos menem's presidency.