https://www.jacksonville.com/story/news/state/2018/10/24/winning-16-billion-mega-millions-ticket-sold-in-south-carolina/9472266007/
article link cited by anon states that South Carolina is one of six states that allow the winner to remain anonymous. At 2% interest, the $1.6 billion jackpot would now be worth about $1.8 billion. The article also notes that most states allow six to twelve months for a winner to claim the jackpot. It did not mention what happens after twelve months. Perhaps things were a bit too hot for Peter Henderson to try to claim the prize.