The Horizon is a type of single-level intercity railroad passenger car used by Amtrak, the national rail passenger carrier in the United States. Amtrak ordered the cars to supplement their existing fleet of Amfleet I single-level cars used on shorter distance corridor trains. The design was based on the Comet railcar used for commuter railroads, but with modifications to make them more suitable for intercity service. Bombardier Transportation built 104 cars from 1988 to 1990 in two basic types: coaches and food service (café) cars.

Amfleet is a fleet of single-level intercity railroad passenger cars built by the Budd Company for American company Amtrak in the late 1970s and early 1980s. Budd based the Amfleet design on its earlier Metroliner electric multiple unit. An initial order for 57 cars in 1973 to supplement the Metroliners on the Northeast Corridor grew to two orders totaling 642 cars, sufficient to reequip all the services on the Northeast Corridor and many other routes around the United States. The first 492 cars, known as Amfleet I and completed between 1975 and 1977, were designed for short-distance service. A second order of 150 cars, known as Amfleet II and completed between 1980 and 1983, were designed for long-distance service. They were the last intercity passenger cars built by Budd.