A little perspective on US distances vs European distances.
According to Google, the distance from Rome to Salerno is 233 km or 144 miles and takes 1 hour 39 minutes.
Washington, DC to Philadelphia is 140 miles or 225 km. Amtrak Acela takes 1 hour 34 minutes from Union Station (DC) to 30th Street Station (Philly). Cost is as little as $30, depending on travel time and day.
Raleigh, NC to Statesville, NC is 146 miles.
Paris to Berlin is 877 km or 545 miles. Train trip is a little over 8 hours. DC to Boston is 435 miles or 770 km. Make it Richmond to Boston and the distance is 535 miles, or 861 km.
Th US is a really big place. Intercity Rail infrastructure is privately built and paid for.
ETA: Florida Brightline rail from Orlando to Miami is 235 miles (378 km) and takes about 3.5 hours. A four pack of round trip coach tickets is $398.