Kelly Clarkson turns 40: a look back (21 images)

Kelly Clarkson sings the national anthem during the United Day of Service Celebration at the Lincoln Memorial in Washington, D.C., on September 11, 2002. The week before, Clarkson won the first, catapulting her career in music. Photo by John Gillis/UPI

Clarkson arrives to perform at the Billboard Music Awards in Las Vegas on December 12, 2003. Photo by Roger Williams/UPI

Clarkson arrives at "WomenRock," Lifetime Television's concert to fight breast cancer, in Los Angeles on Sepember 28, 2004. The following month, Clarkson announced the release of her second album, "Thankful." Photo by Francis Specker/UPI

Clarkson performs in concert in Boca Raton, Fla., on May 6, 2005. The following month, Clarkson's "Breakaway," continued to lead the Billboard Adult Contemporary chart. Photo by Michael Bush/UPI