TALLAHASSEE, Fla. — The winner of last month’s $590 million Powerball jackpot is an 84-year-old woman from Zephyrhills, Fla. Florida Lottery officials made the announcement Wednesday after Gloria C. Mackenzie came forward to claim the prize. They say Mackenzie took the single lump-sum payment of about $370.9 million before taxes. Officials say she is the largest sole lottery winner in U.S. history. She did not speak to reporters outside lottery headquarters, leaving in a silver Ford Focus with family members. The winning ticket was sold at a Publix supermarket in Zephyrhills, a town of about 13,300 people located 30 miles northeast of Tampa. It is best known for bottled spring water that bears its name. The winner had 60 days from the May 18 drawing to claim the lump sum.