US trains were majorly useful and common way to travel before the 1960s. (Only a few miles dropped after WW2.) But in the early 1950s, a plan to build 41,000 miles of Interstate freeways appeared. And Eisenhower selected the Chairman of General Motors to be his Secretary of Defense. The plan was signed into law in 1956, and construction began. It was quite a boon to the auto industry.

By 1967 passenger train ridership had plummeted. Most people and a whole lot of freight shifted to the freeways and/or jetliners. Railroads could not compete. In 1952 there were 370 thousand miles of track. By 1992 that had dropped to 190 thousand miles.[0] Much track steel was recycled, and many rural railbeds became 'trailways'.

[0]https://www.railserve.com/stats_records/railroad_route_miles...