New Jersey, US.-  Two Atlantic City casinos owned by Caesars Entertainment are joining New Jersey’s growing sports betting market this week, and another two in Mississippi will do so in mid-August.

Bally’s casino in Atlantic City started taking sports bets Monday morning. Its sister casino in Atlantic City, Harrah’s, will start taking sports bets on Wednesday.

The company says it soon will offer mobile sports betting, as well, although it did not set a timetable. The gambling industry is closely watching to see which casino will be the first in New Jersey to offer online sports betting following a May ruling by the U.S. Supreme Court on a case brought by the state that cleared the way for all 50 states to offer legal sports betting, should they choose.

Starlette Hedgepath of Halifax, North Carolina, placed the first sports bet at Bally’s, plunking $100 down on the Dallas Cowboys to win the NFC title.

“But not the Super Bowl, even though I wish they would do that, too,” she said.

After gambling until 5 a.m. and grabbing four hours’ sleep, a friend woke her and urged her to return to the casino floor to be there for the start of sports betting. Her bet on the Cowboys was her first sports bet, “not counting one or two at the dog track in Florida.”

“I think this is wonderful for y’all,” she said of New Jersey’s fast-growing sports betting market. “This is going to be big.”

Bally’s and Harrah’s will become the third and fourth Atlantic City casinos with sports betting, joining Borgata and Ocean Resort. Two horse racing tracks, Monmouth Park in Oceanport, and the Meadowlands in East Rutherford, also offer sports betting in New Jersey.

By mid-August, Harrah’s Gulf Coast in Biloxi and Horseshoe Tunica, both in Mississippi, will begin taking on-premises sports bets.

The company says it may expand the mobile betting app to other states besides New Jersey, if and when it makes financial sense to do so.