The National Railroad Passenger Corporation, doing business as Amtrak (reporting mark AMTK), is a government-owned corporation that was organized on May 1, 1971, to provide intercity passenger train service in the United States. "Amtrak" is a portmanteau of the words "America" and "track".  It is headquartered at Union Station in Washington, DC.

All of Amtrak's preferred stock is owned by the U.S. federal government. The members of its board of directors are appointed by the President of the United States and are subject to confirmation by the United States Senate. Common stock was issued in 1971 to railroads that contributed capital and equipment; these shares convey almost no benefits but their current holders declined a 2002 buy-out offer by Amtrak.

Amtrak employs nearly 19,000 people. It operates passenger service on 21,000 miles of track primarily owned by freight railroads connecting 500 destinations in 46 states and three Canadian provinces. In fiscal year 2008, Amtrak served 28.7 million passengers, representing six straight years of record ridership.  Despite this recent growth, the United States still has one of the lowest inter-city rail usages in the developed world due to the relatively developed interstate freeway and airline modes of transportation, and very long distances between cities (giving airlines a significant time advantage).