Amtrak, the Trademark name of The National Passenger Railway Corporation, is the national railway of the United States. Privately-owned passenger trains in the US had always operated at a loss. As car ownership and passenger flights exploded following World War Two, many railroad companies were going out of business, in part because the government required them to provide service.
So Congress passed a law ending this requirement and replacing it with a skeletal network that became Amtrak. It began service in May 1971. Though ridership has rebounded enormously since then, the network is run on a very small budget, so certain priorities have to be set. In the most heavily populated region, the Northeast, the rail system is extensive enough to rival those of Europe and includes a high-speed line. Everywhere else, it's famous for massive delays and unreliability, although high-speed rail is set to be extended to other regions in the next decade (the "Chicago Hub" region—which extends from Cleveland and Detroit to Kansas City east-west and Minneapolis to Louisville north-south—has seen particularly extensive improvements to Amtrak in preparation for it). But if media depict a passenger train in the contemporary US, it will most likely be an Amtrak train.
- Penn Station, New York City is the busiest station in the United States. The original station was a beaux-arts masterpiece that was controversially demolished in 1964 to build the new Madison Square Garden, and the entire station complex is now underground.
- Union Station, Washington DC is Amtrak's headquarters, the second busiest station, and just a few blocks from the capitol building.
- 30th Street Station, Philadelphia is the third busiest station, as it is on the Northeast Corridor and the terminus for every train into the interior of Pennsylvania.
- Union Station, Chicago is the fourth busiest station, hub of the entire Midwestern rail system and the starting point of all but one route to the west coast.
- Union Station, Los Angeles is the fifth busiest station and something of an oddball. It's designed to look like a giant mission-style church complete with gardens, the tracks and platforms are elevated, and it's been in a state of constant expansion since 1989. It was a major hub for Golden Age movie stars and troops bound for the Pacific, and you've seen it many times if you watched 24.
- Northeast Corridor runs from Boston to Newport News and stops in every major city in the northeast. Due to the area's high population density, it is one of the few Amtrak lines that turns a profit; it and the Acela Express together generate more than half of the entire system's revenue.
- The Acela Express is currently America's only high-speed line, from Boston to Washington DC. It manages to run on normal tracks by tilting the cars with hydraulics. The ride itself is very smooth and eerily quiet, though a lot slower than comparable systems in other countries—the average speed (including stops) is only 80 miles per hour, only reaching its top speed of 150 miles per hour on a few stretches. Expect to see members of Congress from the northeast riding it to/from DC at the beginning and end of each week, or people traveling between New York City and Boston (two-fifths of all train and air traffic between the two cities is on Acela).
- The Pacific Surfliner is the busiest line in the West, from San Diego to San Luis Obispo by way of Los Angeles, and yes, quite a lot of it runs right along the beach. Especially popular with military personnel, college students and weekend vacationers.
- The Capitol Corridor is Northern California's answer to the Pacific Surfliner, running from San Jose to Auburn (and soon[when?] Reno) by way of Oakland and Sacramento. Amtrak notably does not reach San Francisco. Popular with state officials.
- The Keystone Service from New York to Harrisburg via Philadelphia.