Lee won $1 million and a show in Las Vegas from November 7-10.
Lee, who is blind and autistic, was hailed throughout the season for his soulful, moving performances and he and his mother Tina jumped for joy when the announcement was made. It was Union's first year as judge, and her first "golden buzzer" to keep him in the running was for Lee.
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"Everybody rooted for him, and he's probably one of the most popular winners we've had on one of these shows", said Cowell.
Not that Lee needed it though, as he astounded every person in the Dolby Theatre in Los Angeles, California, with his performance that went viral.
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Government for "black hand" tactics and publically identified U.S. diplomatic personnel, putting them at risk", he told the panel. Translated and edited by Luisetta Mudie.
Born with optic nerve hypoplasia and being diagnosed with autism when he was just four years old, Lee has become an inspiration since he first appeared on the show.
After an wonderful performance, Kodi posed with Leona Lewis on the America's Got Talent red carpet.
Detroit Youth Choir finished second; comedian Ryan Niemiller finished third; acrobatic dance group V. Unbeatable finished fourth; and the Voices of Service quartet finished fifth.
When his name was read out as the victor, Lee jumped for joy while holding his mother Tina's hand as confetti rained down.
"I'm extremely proud [of Lee]".
Judge Simon Cowell said that from the beginning, Lee's audition would be something he would "remember". He's got an awesome talent... "How do you feel?" host Terry Crews asked. "It in actual fact has saved his life taking half in tune".