The single winning ticket in SC is officially worth $1.537 billion as an annuity or a lump sum cash prize of $877.8 million.
The victor has not been identified.
The six winning numbers drawn on Tuesday night were five, 28, 62, 65, 70 and another five as the special "gold Mega Ball".
A flimsy little piece of paper that crossed the counter of a convenience store on a country road in SC is now worth $1.537 billion, so lottery officials could hardly be blamed Wednesday if their excitement seemed colored by anxiety.
The new amount makes the prize the second largest, just shy of the $1.586 billion jackpot for a rival Powerball lottery in January 2016, which was shared between three winning tickets.More news: QUIZ: How much do you remember about Mo Salah's 50 Liverpool goals?
"This is truly a historic occasion".
The victor has the option of taking the cash lump sum of $913 million before taxes, or an annuity of $1.6 billion in 30 payments.
If no one had matched Tuesday's numbers, officials say the next drawing would have been for an estimated $2 billion jackpot.
It was split three ways by ticket holders in California, Florida and Tennessee. A US$1.5 million investment in Microsoft Corp in 1986 would be worth about US$1.6 billion today.
Anyone who hits all six numbers to win the jackpot can choose an immediate cash payment of US$904 million or receive the US$1.6 billion prize over 29 years.
A group of hospital employees in Mount Pleasant won a $1 million prize in Tuesday night's Mega Millions drawing.More news: Amazon sees slower global growth, cites late Diwali sales
The next jackpot victor could come from anywhere.
Three tickets sold in Florida won a million dollars each, there was also a three million dollar victor.
In case you hadn't already guessed, the massive jackpot is the world's largest ever lottery grand prize.
The lottery jackpot now falls to $40 million and the next Mega Millions drawing is Friday, said a Mega Millions press release.
Tickets had to match all five white balls and the yellow Mega Ball to claim total victory. They remember selling a $10,000 victor once, but never a prize anywhere near $1 million.
The Powerball drawing is tonight and the jackpot for that is an estimated $620 million.More news: Data is being "weaponized" against users
Mega Millions followed suit in October 2017, resulting in the odds worsening from 1 in 259 million to 1 in 302.5 million.