After hearing her singing in the school halls, a teacher pressures Clarkson to join the school choir. "Singing gave me confidence," Clarkson tells the Orange County Register. "Friends at school were nervous because they didn't know what they wanted to do with the rest of their lives, but I had a peaceful feeling inside, because I knew. I knew that I would make a living at this since a seventh-grade assembly."
After graduating from Texas' Burleson High School, Clarkson records a demo financed by pal Jessica Huggins. While shopping her tapes, Clarkson begins a string of menial jobs. "I kept getting doors slammed in my face," she tells PEOPLE. Two years later, she saves enough money to move to L.A. But, her West Coast sojourn ends abruptly when her apartment building – with all her belongings – is reduced to ashes. "I decided to cut my losses and go home," she tells PEOPLE.
A friend encourages Clarkson to try out for the talent show American Idol at the Dallas open call. The night before her audition she is so nervous she can't sleep. "I didn't have a clue what I was walking into," Clarkson tells Teen People. She blows the judges away and earns a place to compete in L.A.
In a two-hour Fox special, Clarkson captures 58 percent of 15.5 million votes with her teary-eyed performance of "A Moment Like This," securing the first American Idol title. "In the end, I couldn't hear them say I won," she tells Teen People. "I actually found out when Justin Guarini hugged me and said, 'Congratulations.'"
Clarkson's debut album, Thankful, is released. Though her first single, "A Moment Like This," has already topped the charts, selling nearly 250,000 copies its first week, Clarkson tells PEOPLE, "I'm terrified. I can sing in front of millions of people and not be nervous at all, but release an album and it makes me a basket case." She needn't worry; Thankful goes on to sell more than 2 million copies.
In a box office blunder, Clarkson makes her film debut alongside Idol runner-up Guarini in From Justin to Kelly, a musical comedy reminiscent of 1950s beachcomber movies. Later, Clarkson tells Time, "I knew when I read the script it was going to be real, real bad, but when I won, I signed that piece of paper and I could not get out of it. Two words: contractually obligated."
Clarkson climbs back on the tour bus for a 32-city run with Idol Season 2 finalist Clay Aiken, who quickly learns Clarkson's first rule of the road. "Don't wake Kelly up in the morning," he cautions Teen People, "because she'll want to kill you." Nevertheless, the friends decide to share a bus. "We're from the South," Clarkson says. "We want to save money."
After her feature film flop, Clarkson openly admits she never fancied herself an actress. But, she scores her second guest spot on NBC's 1960s drama American Dreams, as pop singer Brenda Lee (her first guest role on the show was in September 2003).
Clarkson releases her second album Breakaway. She writes six songs on the album, including "Since U Been Gone," "Because of You" and "Behind These Hazel Eyes," which all hit the No. 1 or No. 2 spots on the Billboard charts. The album sells more than 5 million copies, making it the third best-selling album of 2005 and solidifying Clarkson's place as the real deal.
Clarkson is invited to perform on SNL, where host Jason Bateman's introduction omits any reference to Idol, signaling the singer's successful transition from talent show phenom to full-fledged stardom. "I never thought I'd like anything she did," says Kelly Osbourne. "But I'm sorry. I'm obsessed with her CD. I have friends in the heaviest hardcore bands, and they have 'Since U Been Gone' as their ring tone."
BIOGRAPHY (top to bottom): Classmates Yearbook Archives; Rob Daly; Fred Prouser/Reuters/CORBIS; Lester Cohen/Wireimage; 20th Century FOX/Everett; ERICA BERGER; NBC; Everett Collection