In 1922, the JGR commissioned two electric locomotives, which were numbered 1000 and 1001. They had been manufactured by Baldwin and Westinghouse in the USA and followed the box cab design that was common there at the time. They were first used in the Tokyo area on the Yamanote line and on the Chuo main line. What was special about these lines was that the catenary carried either 600 or 1,200 volts, depending on the section, and the locomotives had to be designed for both voltages.

From 1925 the locomotives were used on the Tokaido main line, freshly electrified with 1,500 volts, after they had been modified accordingly. From 1928 they were designated ED10 1 and ED10 2 according to a new scheme. They were retired from the JNR in 1959 and 1960 respectively. The number 2 was then sold to the Seibu Railway and used there until 1986 to pull freight trains. It was preserved and is now in Yokoze in its original color scheme.