[1] The railcars were intended, in case of increased threat of nuclear war, to be deployed onto the nation's rail network to avoid being destroyed by a first strike counterforce attack by the Soviet Union.

However, the plan was canceled as part of defense cutbacks following the end of the Cold War, and the Peacekeeper missiles were installed in silo launchers as LGM-118s instead.

On December 19, 1986, the White House announced that U.S. President Ronald Reagan had given approval to a plan for the development of a railroad-based system for basing part of the planned LGM-118 Peacekeeper – originally referred to as MX for "Missile, Experimental" – intercontinental ballistic missile (ICBM) force.

Rail Garrisons would resemble small freight yards with four spurs leading to slant-sided steel and earthen hardened shelters to house the trains.

Upon the receipt of a signal indicating an increase in alert level, the trains would be "flushed", dispersing onto the American railroad network,[6]: 281  thus making it difficult for an enemy to determine where the missiles were at any given time to target them.

[3] Major contractors for the rail garrison system were Boeing Aerospace Corporation, Westinghouse Marine Division and Rockwell International Autonetics.