Delaware Governor John Carney holds a $10 bill he used to place the first bet at Dover Downs Casino. (Mark Makela/Getty Images)

DOVER, Del. — Gov. John Carney reached into his pocket shortly before 1:30 p.m. Tuesday and pulled out a folded bill.

“This $10 bill is going to bring our Phillies back,” he said.

He walked over to a teller at the Dover Downs sportsbook and placed the first legal sports wager in the state of Delaware, betting on the Phillies to beat the Cubs later that night, and ushering in a new era for sports gamblers in the United States. Delaware became the first state to start accepting sports wagers since the Supreme Court overturned a federal law last month that largely outlawed sports betting outside of Nevada, and others are already racing to follow suit.

“Gloating in this business doesn’t last very long,” said Carney, the state’s first-term Democratic governor. “We’re happy to be first today. … I  don’t expect we’ll be the only one for very long. But today it feels pretty good to be first.”

The Supreme Court decision is expected to have far-reaching effects — experts suggest that illegal betting in the United States is a $50 billion to $150 billion industry — but for the time-being, Delaware will be the only new state in the sports gambling business. Tuesday’s early start means that sports gamblers in the Mid-Atlantic could be a short drive away wagering on a variety of sporting events, from the NBA Finals to the World Cup, from Major League Baseball to the Capitals’ pursuit of the Stanley Cup.