ZEPHYRHILLS — An 84-year-old Zephyrhills woman who rarely left her tiny duplex stepped forward Wednesday as the winner of the largest single jackpot in American lottery history, valued at $590.5 million.

Shortly after claiming her prize, Gloria C. MacKenzie stepped back into the shadows.

Lottery officials announced midmorning that the Powerball winner had arrived with the lone winning ticket, which was sold last month at a Zephyrhills Publix.

"They walked right through the headquarters of the Florida Lottery here in Tallahassee and said, 'I have a winning ticket and I'd like to validate it,' " Lottery Secretary Cynthia O'Connell said at a news conference.

MacKenzie, her face hidden behind large black sunglasses, arrived with her son Scott, a family friend and her financial and legal advisers. She said nothing to the pack of reporters who swarmed her.

Neighbors in Zephyrhills said that guarded profile fits with what they know of MacKenzie.

"She liked to talk, but not with everybody," said Jorge Trapero, who lives in the apartment attached to MacKenzie's, across from a cow pasture.

He said she was strong: "Sometimes she'd come from the store to buy something and I'd see her over there taking the bags. 'Gloria you want some help?' She'd say, 'No, no, no, it's okay. I can do it.' "

Neighbor Bruce Featherston described the area as working class — "where people are really struggling."

"I assumed she was just an elderly lady scraping to get by," he said of MacKenzie. "She never had anything fancy."

Now she's walking away with a lump sum payment of more than $370 million, before taxes.

• • •

In a statement, MacKenzie called the winnings a blessing, and recalled how a person in line at Publix allowed her to go ahead to buy her single Quick Pick ticket.

Mindy Crandell, 34, was in line at Publix with her two daughters that day, she said, when a woman stepped in front of her.

"I don't know that she was intentionally cutting," Crandell, who lives in Dade City, said in an interview Wednesday, "or maybe she didn't realize she did it."

Crandell let it go. She was worried about keeping her 5-year-old, Jeffa, entertained.

Later, when she heard about the winner she couldn't help but think it might have been the same woman. The she saw MacKenzie's picture.

"I said, 'You have got to be kidding me.' Of course they win the biggest lottery in U.S. history."

But she's not upset. Maybe that woman needed it more than she did, she thought.

According to lottery spokesman David Bishop, their chance encounter didn't cheat Crandell out of the fortune.

"Each lottery terminal has its own random number generator and there are a lot of factors," he said. "If there was even a millisecond difference in the time between key strokes at the terminal, it would have changed the numbers."

Crandell sees the incident as a lesson for her daughters. When she asked her 10-year-old, Mallory, about it, her daughter gave an answer that made her proud.

"It's better to be polite than to be rich," Mallory said.

• • •

MacKenzie's statement said she and her son Scott, who lives in Jacksonville, had a standing agreement to split their winnings. To the rest of MacKenzie's extended family, the news was a surprise.

"We were flabbergasted,'' Gloria MacKenzie's sister-in-law, Ella MacKenzie, said. "We are very pleased for her. That is a wonderful thing. She is a widow and I'm sure she will find uses for it.''

MacKenzie was a homemaker in East Millinocket, Maine, near Bangor, raising her four children, Ella MacKenzie said. Gloria's husband, Ralph, worked for Great Northern Paper, the town's major employer, and loved to hunt, fish and play golf. The couple wintered in Florida until he died in 2005, then Gloria Mac­Kenzie moved to Florida for good.

On Wednesday, her empty Zephyrhills apartment had a sticker affixed to the front door of a hand raised in a stop sign with the words "private, no soliciting."

Dawn Gourlay, whose home sits just east of MacKenzie's, said MacKenzie stayed inside her air conditioned duplex so much that sometimes when she went outside for a walk she would not be properly dressed for the weather.

"She didn't know if it was too hot or too cold," Gourlay said.

• • •

The MacKenzies left lottery headquarters in a silver Ford Focus. By 6:30 p.m. it was parked in the driveway of the Jacksonville home where Scott lives. It's near a tributary that feeds into the St. John's River. Car lots and a bowling alley are down the street.

Most of the homes in the neighborhood, in a working class section of Jacksonville called the Lakeshore area, were built in the post-World War II years and suggest the art-deco style that would remake Florida in the 1950s.

Neighbors said Scott Mackenzie, who lives at the home with another man, moved his mother to the house about two weeks ago. No one answered the door Wednesday night.

"I wish they had kept the winner confidential," said Ted Reynolds, a barber who lives next door. "You media guys are just going to hound him."

A local TV truck parked outside the house most of the night, its towering satellite pole blinking in the night, outshining the dimly lit street lights.

Reynolds and another neighbor, Stephen Harris, both moved to the neighborhood about a month ago and said they don't know Scott Mackenzie well.

"They're quiet and keep to themselves," said Reynolds, 34. "I probably won't get to know them after this. They'll probably move away."

Said Harris: "I feel bad for them. They just wanted their privacy."

Harris, who works in a paint body shop, grew up in this neighborhood. Now 40, he moved back to live with his mother because of hard times. He used to know everyone in the neighborhood, when times were better. Now, he said, everyone is more private.

"Back in the 1950s, this was an ideal home," said Harris, who said the house doesn't have washer and dryer hook ups.

"It's very strange," Harris said about the biggest lottery winner in history living across from him. "I hope they do what I would do and help the neighbors out. Not give them money, but call a contractor and give everyone credit with him. Upgrade their homes, fix up their cars. It's the neighborly thing to do."

Times staff writers Joey Knight, Jon Silman, Stephen Nohlgren, Dan Sullivan and Octavio Jones and researcher Carolyn Edds contributed to this report.