Firemen from Highland Beach, Fla., were heading to a conference in Miami, a money manager to his office in Boca Raton. Families with young children wearing Mickey Mouse ears and toting Little Mermaid backpacks, filled the train’s sun-soaked four-seaters on their way to or from Disney cruises and various theme parks.

Florida, of all places, has been rebooting intercity passenger rail travel in America. Back in the late 19th century, the oil tycoon Henry Flagler built a railroad down the state’s Atlantic coast that fast-tracked Florida’s growth and put cities like Miami and Palm Beach on the map. Then the automobile proliferated.

Now a privately owned service called Brightline, operating on Flagler’s old line, is making a 21st-century pitch for the enduring virtues of train travel, moving passengers 235 miles between Miami and Orlando, with a few stops in between, and hopes to reach Tampa.

The company is pursuing a second service, too: a $12.4 billion, 218-mile, all-electric train that will link Las Vegas with Los Angeles, or more precisely, Rancho Cucamonga, Calif., where riders can connect with the California Metrolink to L.A. It aims to be America’s first genuine high-speed rail. The project, unlike the one in Florida, whose construction costs have nearly all been paid by Brightline, has received $3 billion in promised federal grants. The company’s hope was to have service up and running before the 2028 Summer Olympics in L.A. The goal now, according to Brightline officials, is the end of 2028.

With intercity rail travel struggling in America, is a private company the fix? It’s a truism that trains are potent engines of urban and economic development. But can they make money?