Designed in the 1970's by the Land Systems Division of the General Dynamics Corporation in response to the U.S. Army's MBT-70 program, the first M1 rolled off the assembly line in 1978. After two years of acceptance trials, the first of these vehicles was delivered to the US Army on February 28, 1980. By 1985, evaluations of field service had prompted the first modification requests, and production shifted to the M1A1. The first M1A1's were delivered to units in August of 1985. The Army has converted 368 older M1s to M1A2s. An additional 580 M1s are being upgraded to A2s under a five-year contract awarded in FY1996, with a total of 998 M1 upgrades planned. In 1999 the Army began upgrading M1s to the M1A2 System Enhancement Program (SEP) configuration. The SEP embeds digitization capabilities inside the Abrams' electronic architecture, eliminating the requirement for electronic appliques.
