1974 saw the introduction of electric subway and commuter train service to Seoul. The initial service, now Seoul Subway Line 1, consisted of a 6-mile underground track under downtown Seoul, with continuing service on through trains on three mainline routes out of Seoul, reaching Incheon and Suwon. The rolling stock was Korail 1000 Series and Seoul Metro 1000 Series, based on similar Japanese subway train designs of the day.

This is Car 1001, part of Consist 101, the very first train that entered service on August 15, 1974, the subway service's opening day. The first fourteen consists were sourced from various Japanese manufacturers, and Car 1001 was built by Hitachi, while subsequent consists were locally assembled by Daewoo Heavy Industries using Japanese components. Car 1001 remained in service until 2000.

The blue paint job with white window stripe was inspired by naval colors, and was commonly seen on all Korail trains of the day. The sight of this train was very iconic of Seoul in the 1970s and the 1980s.