NASHVILLE (AP) - Country legend Dolly Parton joined Gov. Bill Haslam in celebrating the 10th anniversary of her Imagination Library in Tennessee.

Parton, Haslam and former Gov. Phil Bredesen were part of a ceremony on Tuesday that capped a statewide bus tour promoting the program, which started during Bredesen's administration.

The Imagination Library has mailed over 20 million free books to Tennessee children since it began. The Books from Birth Foundation helps support the program by matching the funds raised by local groups.

Parton said her main reason for starting the program was to honor her father, who couldn't read or write.

The more than 50-county bus tour that began Aug. 26 included recognizing the work of volunteers and donors, signing children up for free books and building community support for the program.