Dreams of quitting an uninspiring job, helping the needy and travelling the world opened American wallets on Wednesday for a chance to win the biggest-ever $1.5 billion Powerball lottery jackpot.

The frenzy to buy tickets was expected to push the largest-ever U.S. lottery prize even higher by the time the six winning numbers are picked at the drawing at 10:59 p.m. EST (0359 GMT) on Wednesday at lottery offices in Tallahassee, Florida. It is the world's largest potential prize for a single winner.

The jackpot is worth nearly $930 million if a winner chooses an immediate cash payout instead of annual payments over 29 years, according to the Multi-State Lottery Association. Powerball is played in 44 states, Washington, D.C. and two U.S. territories.

It may take several hours to determine if anyone has picked the six winning numbers, said Gary Grief, executive director of the Texas lottery, at a news conference.

If no one holds the winning numbers, the jackpot will be rolled over for Saturday's drawing, pushing the annuitized prize to an estimated $2 billion, with a cash value of $1.24 billion, said Kelly Cripe, spokeswoman for the lottery in Texas, one of the participating states.

"If I win, I'll give it all away to poor people," said New York restaurant deliveryman Osman Gamie, 43, after buying a dozen of the $2 tickets at a midtown Manhattan grocery.

"I don't like to live like the rich man - too many headaches," said Gamie, a new U.S. citizen from Bangladesh.

The ticket-buying mania was expected to reach a rate of $1.3 million per minute during the evening commuter rush hour, Grief said.

Powerball sales are "exponentially higher" than normal, Grief said. Since the jackpot was last hit on Nov. 4, 2015, a total of $2.65 billion in Powerball tickets have been sold, including $133 million sold on Wednesday by midday, Grief said. Odds of picking a winning combination are 1 in 292 million.

For every $1 worth of Powerball sales, 50 percent goes to prizes, 40 percent to causes such as education, and 10 percent to retailers who sell the tickets and other administrative costs, Grief said.

"It's amazing; it's crazy," said Milwaukee Wal-Mart worker Juan Galindo, 41, who sought to pump up his luck by purchasing tickets at three different locations in Wisconsin over the past two days. The father of two said winning would allow him to build his dream house.

In New York, a steady stream of lottery ticket buyers braved some of the most frigid temperatures so far this winter and flowed into the tiny grocery store in midtown Manhattan.

Tatiann Cave, a 23-year-old home health aide, said she would use the jackpot to start her own cosmetics business. She has been using her mother's kitchen in New York to cook up test batches of products she dreams of selling under the name "Black Goddess."

"I'd like to quit my job and do something inspiring," Cave said.