While the US was a passenger train pioneer in the 19th century, after WWII, railways began to decline. The auto industry was booming, and Americans bought cars and houses in suburbs without rail connections. Highways (as well as aviation) became the focus of infrastructure spending, at the expense of rail.

The lack of a robust high-speed rail system in the United States is the result of a complex interplay of geography, history, and policy. Unlike Europe or Japan, the U.S. developed its modern infrastructure during the post-WWII era, which coincided with the rise of the automobile industry and the Interstate Highway System. Massive federal subsidies were poured into highways and airports, while passenger rail was largely left to private companies that eventually went bankrupt or transitioned to freight. Geography is also a major factor; the sheer distance between major U.S. cities (outside of the Northeast Corridor) makes rail construction prohibitively expensive and less competitive against air travel. Furthermore, most tracks in the U.S. are owned by freight companies (like Union Pacific), which legally prioritize slow, heavy cargo trains over Amtrak’s passenger service, leading to frequent delays. Finally, "Right of Way" issues and environmental regulations make building new, straight tracks for high-speed trains a legal and financial nightmare. However, projects like Brightline in Florida and the California High-Speed Rail are currently attempting to prove that modern rail can succeed in specific "mega-regions."