Pete Seeger composed "Where Have All the Flowers Gone" (Seeger - Hickerson) to the tune of an old Russian folksong in 1955. It's part of a medley on the Folkways 1960 release "The Rainbow Quest". Director of the Archive of Folk Songs at the American Folklife Center of the Library of Congress, Joe Hickerson had completed the tune in 1960.
The Kingston Trio recorded the cover for the album "College Concert" and the hit version in 1961 with the single reaching number 21 even though it was released as a B side. It's been said that the Trio watched Peter, Paul and Mary sing the song in concert and the next day they went into the studio to record their cover thinking it was an old folk song.