Definition: The word "Amtrak" is a brand name for Amtrak (formerly known as American National Railway Company) in the United States. It's a subsidiary of the Amtrak Corporation, a joint-stock corporation that operates an extensive system of intercity passenger trains throughout North America and internationally. The word "Amtrak" was originally used to refer to the Union Pacific Railroad in the United States until it merged with the Kansas City Southern Railroad in 1972. However, after that date, Amtrak became its own separate company, operating as a brand under American National Railway Company. The term has evolved over time and is now commonly used by various public transportation companies to refer to their respective systems. Amtrak's trains are primarily service-oriented with regular passenger services between major cities across the United States (the "Main Line" in Washington, D.C.; the "Midwest" route through Michigan; and a series of regional routes serving the Pacific Northwest). The company also operates intercity rail service in Canada, providing express, coach, and luxury-class train services. The word "Amtrak" is often used as an acronym to remember the name, but it can also be seen as a slang term for "Amtrak."