Juli Cragg Hilliard

Mary Wilson, upbeat and articulate, is on the phone from Boca Raton, where she has a corporate date. She sings at a mix of public concerts and private gigs -- during Super Bowl-related festivities in Detroit, she says, she'll sing the national anthem at a boxing match.

"And since I'm from Detroit, you know, they called me."

Detroit -- that's where Wilson, Diana Ross and the late Florence Ballard formed a group that eventually became a glamorous and almost mythic trio, the Supremes.

In the '60s, the group was the most successful artist on the Motown label via a cascade of lush pop hits that represent the soundtrack of an era: "Where Did Our Love Go," "Stop! In the Name of Love," "You Can't Hurry Love" and more.

Wilson will perform at 7:30 p.m. Feb. 15 at the Florida State Fair. In recent publicity photos, she's still a poster girl for eternal gorgeousness. What's her secret?

"I pray a lot," said Wilson, a grandmother of eight who will turn 62 in March. "I guess I have good genes. My mom was an incredible-looking woman. She died when she was in her 80s, and she looked like she was in her 50s."

When the Supremes officially disbanded in 1977, Wilson was the only member to have stayed from the start to the end. Ballard departed in 1967 and died of cardiac arrest at age 32 in 1976. Ross left in 1970.

Wilson started a solo career and acted in movies and on television. She wrote a best-selling autobiography, "Dreamgirl: My Life as a Supreme" (1986) and a sequel, "Supreme Faith: Someday We'll Be Together" (1990).

In addition to concerts and inspirational lectures based on her rags-to-riches story, Wilson is involved in a movement among vocal artists of the '50s and '60s to combat knockoff groups that pass themselves off as the originals.

"They've taken our history, but they don't have our DNA," Wilson said.

Perhaps her involvement was stirred by a Supremes "reunion" in 2000 in which Ross toured under the name with Lynda Laurence and Scherrie Payne, two women who hadn't joined the band until the '70s. At the time, Wilson said she was "devastated" over the exclusion of herself and Cindy Birdsong, who replaced Ballard. Now, she refuses to talk about Ross in interviews.

Last month, Laurence and Payne marked the 20th anniversary of Former Ladies of the Supremes, a trio they have with non-Supreme Freddi Poole.

At any rate, the movement, which includes the Vocal Group Hall of Fame, is starting with state laws and working up to federal. Last week, Wilson testified before an Illinois House committee.

"They asked me, 'How do we know you're the real Mary Wilson?'" she said. "So I had to sing my background vocals for them."

Wilson is one of nine cultural ambassadors for the U.S. State Department. In November in Bosnia-Herzegovina, to commemorate the 10th anniversary of the country's peace accords, she was keynote speaker at a youth conference and sang at a series of concerts the State Department described as standing-room-only.

At the end of a show, Wilson said, she and the audience -- a mix of ethnicities -- sang "Someday We'll Be Together."

"It was so beautiful," she said.