Belgrano Cargas S.A. was an Argentine State-owned company which operated the 10,841 km (6,736 mi) 1,000 mm metre gauge gauge freight rail network built by Central Northern and Province of Santa Fe Railways, which became part of Belgrano Railway network after railway nationalization of 1948.

The General San Martín Railway (FCGSM), named after the former Argentine general José de San Martín, was one of the six state-owned Argentine railway companies formed after President Juan Perón's nationalisation of the railway network in 1948. 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.