The foreign investment provided by these companies had helped to transform Argentina from a relatively underdeveloped, rural country, with many isolated communities, into one which was becoming an increasingly prosperous agricultural producer and exporter.

The rail networks of the various companies generally radiated inland from the major ports of Buenos Aires and Rosario and were primarily designed to speed the export of agricultural products from the provinces to European markets.

During World War II it had not been possible to import railway equipment or materials which meant that there was an urgent need for track, locomotive and rolling stock renewal by the time nationalisation took place in 1948.

After the nationalisation all the Argentine network was grouped into six railway divisions named after distinguished Argentine presidents and national heroes (such as José de San Martín, Manuel Belgrano, Domingo Sarmiento, Justo José de Urquiza, Bartolomé Mitre and Julio A. Roca) according to their track gauge and locality.

At the time there was little local opposition, although later it became apparent that, far from stimulating the national economy, nationalisation of the railways together with other foreign companies, contributed to the economic crises that Argentina suffered from the 1950s onwards by adding substantially to national budget deficits (which the Central Bank was forced to finance largely by "printing money", leading to inflation).