Amtrak's Heritage Fleet consisted of the rolling stock provided to it when it assumed passenger service on commercial railroads.

When Amtrak took over most intercity passenger service in the United States in 1971, the company selected the best equipment from its predecessor railroads.

[2]: 108 Amtrak used its secondhand equipment across its national system – often with cars from multiple railroads seen in a single train, creating the "Rainbow Era".

[2]: 114–115, 170 The unusually harsh winter of 1976–1977 sidelined much of the steam-heated fleet, causing cancellation of most Amtrak service in the Midwest for two months.

[6][7] Beech Grove was initially to handle all 500 cars selected for HEP conversion, but 175 were overhauled elsewhere to speed the process.

[7] On October 15, 1979, the Lake Shore Limited was the first Amtrak route to be permanently assigned HEP-equipped Heritage Fleet cars.