Denver's next album, Poems, Prayers and Promises, released the following year, was a breakthrough for him in America, thanks in part to the single "Take Me Home, Country Roads," which went to number two. (The first pressings of the track were distorted. Its success was in part due to the machinations of his new manager, future Hollywood producer Jerry Weintraub who signed Denver in 1970. Weintraub insisted on reissues of the track & began a radio-airplay campaign that began in Denver, Colorado) His career flourished from then on, and the hits came pouring in for the next four years. In 1972, Denver scored his first top ten album, with Rocky Mountain High, while its title track reached the Top Ten in 1973. In 1974, "Sunshine on My Shoulders" and "Annie's Song" both went to number one, and "Back Home Again" made it to number five. In 1975, he again had two number ones, "Thank God I'm A Country Boy" and "Calypso/I'm Sorry," and a top twenty hit, "Sweet Surrender." Key to Denver's success were his many appearances on television, which in the pre-MTV era of the 1970s, with his long blond hair, embroidered 'western' shirts, affable manner & granny glasses, made him one of the first truly "tele-genic" pop stars. His manager, Jerry Weintraub, insisted on these appearances, (including a series of half-hour shows in England despite Denver's then-protestations that "he had had no success in Britain ... I mean none") for as Weintraub told Maureen Orth of Newsweek in December 1976, "I knew the critics would never go for John. I had to get him to the people." Among one of these first appearances was a spot filling in for Johnny Carson on The Tonight Show. During the show, Denver uttered the phrase, "Far Out!" over nineteen times, thus ensuring the exclamation would become a sort of catchphrase forever associated with his name. After appearing as a guest on many shows, Denver went on to host his own variety/music specials, including several world-televised concerts from Red Rocks Amphitheatre near Denver, the "Mile High City". His seasonal special "Rocky Mountain Christmas" was watched by over 60 million people and was the highest rated show for the ABC Network at that time, while his live concert special, "An Evening with John Denver" won the Emmy award for Best Variety or Musical Special of the same year.
He also made appearances on The Muppet Show. This relationship was the beginning of a life-long friendship between Denver and Jim Henson which spawned two television specials Denver made with The Muppets. He even tried his hand at acting starring in the 1977 film, Oh, God! opposite George Burns. Denver would go on to host the Grammy Awards five times in the 1970s and 1980s, as well as guest-host The Tonight Show multiple times.
1972's Rocky Mountain High
In 1975 he was recognized as the Country Music Association Entertainer of the Year. At the Country Music Association awards ceremony, reigning Entertainer of the Year Charlie Rich (who himself had a series of crossover hits) was to present the award to his successor; instead of reading the name of the winner, he set fire to the envelope with a cigarette lighter and announced in tones of disgust, "My good friend, John Denver!". Some considered it a statement against country pop and the Music Row-controlled Nashville Sound, while others rejected Rich's actions.
In 1977, he co-founded The Hunger Project, along with Werner Erhard and Robert W. Fuller. Denver served for many years, and supported the organization until his death. He was also appointed by President Jimmy Carter to serve on the President's Commission on World Hunger. He wrote and dedicated the song "I Want to Live" as the theme song for the Hunger Project.
In 1979, he performed "Rhymes & Reasons" at the Music for UNICEF Concert, which gained him exposure to worldwide audiences. Royalties from the concert performances were donated to UNICEF.