The first horse-racing track in America was established in 1665. We’ve gotta go way back, before America was actually the United States. Let’s start at the horse track a couple of centuries ago. Why haven’t more of them already allowed it? Sports betting has been illegal in most of the country for generations.
All the court did was wipe out a federal ban on more states permitting sports gambling. A big Supreme Court decision in May 2018 opened the door for legalized sports betting in America, but it didn’t make it legal on its own.