"Leaving on a Jet Plane" is a song written by John Denver in 1967 uring a layover at an airport in Washington and recorded by the Mitchell Trio that year. The original title of the song was "Oh Babe I Hate To Go" but Denver's then producer, Milt Okun, convinced him to change the title. Denver wrote the song after his flight was delayed. He would later call the hours waiting for the next flight the most profitable of his life. Others covered the song in 1967, including Spanky & Our Gang and Peter, Paul and Mary on Album 1700. It did not become a hit until Peter, Paul and Mary released it as a single in 1969. It turned out to be their biggest (and final) hit, becoming their only #1 on the Billboard Hot 100 chart in the United States.