Dolly Parton explains the inspiration behind her Imagination Library, a book gifting program that mails free, age-appropriate books to registered children from birth to age five. | Dolly Parton's Imagination Library

In 1980, Dolly Parton brought the full range of her talents to bear on a project that would cement her crossover from country music to mainstream superstardom. The project was the movie, 9 to 5, for which Dolly wrote and performed the song that earned her both Oscar and Grammy nominations. It was the biggest hit of Dolly Parton’s career as it reached #1 on the pop charts on #ThisDayInHistory in 1981. To learn more, visit: https://www.history.com/this-day-in-history/dolly-parton-cements-her-cross