Washington Union Station, known locally as Union Station, is a major train station, transportation hub, and leisure destination in Washington, D.C. Designed by Daniel Burnham and opened in 1907, it is Amtrak's headquarters, the railroad's second-busiest station, and North America's 10th-busiest railroad station. The station is the southern terminus of the Northeast Corridor, an electrified rail line extending north through major cities including Baltimore, Philadelphia, New York City, and Boston, and the busiest passenger rail line in the nation. In 2015, it served just under five million passengers.

MARC is a commuter rail system in the Washington–Baltimore area. MARC is administered by the Maryland Transit Administration (MTA) and operated under contract by Alstom and Amtrak on track owned by CSX Transportation (CSXT) and Amtrak. In 2023, the system had a ridership of 3,860,600, or about 12,400 per weekday as of the fourth quarter of 2023, less than pre-COVID-19 pandemic weekday ridership of 40,000.