Shortly after World War II, General Electric built 20 heavy electric locomotives for the Soviet Union. They were equipped for 3 kV DC and had an output of 5,525 hp. Each locomotive had two trucks with four driving axles and two leading axles on a sub frame. Due to the beginning of the Cold War, they were not delivered to the Soviet Union. Instead they were offered to US customers, so that only the first 14 were built in broad gauge and the last six got standard gauge trucks from the beginning.

The first three were bought by the Chicago South Shore and South Bend Railroad and used in freight service. Since their lines were electrified with 1,500 V, they were used at a reduced power setting. After being retired in 1981, two are still on static display. The Companhia Paulista de Estradas de Ferro in Brazil bought five and converted them to 5 ft 3 in broad gauge. They were used until 1999 and also two are still on display.

The largest part with 12 locomotives was bought by the Milwaukee road and got the nickname “Little Joe” after Joseph Stalin. All which had been built in Russian broad gauge were converted to standard gauge. As it turned out that the power supply of the line was not powerful enough to power two at maximum power, they were initially operated at reduced settings. Later the power supply was upgraded and the line voltage increased from 3,000 to 3,400 V.

Ten were to be used in freight service and were designated EF-4. For use with the Olympian Hiawatha, two received roller bearings and a steam generator and were designated EP-4. Later one cab was removed from the freight locomotives and multiple controls were added. Their service ended in 1974 when electric operations were stopped. Today E70 survives on static display at Deer Lodge.