"If I Had a Hammer" was written by Pete Seeger and Lee Hays in 1949, and was first recorded by their band the Weavers. The Weavers were one of the first bands in popular music to seize on the traditions inherent in the evolving field of folk music, dig up old traditional songs, and create brand new songs in that same tradition. Their music was heavy on harmonies and acoustic instrumentation, bringing the acoustic guitar into the front of the band as a primary instrument in the performance of folk music (though Seeger's banjo was also a focal point).
More than a decade later, in 1962, the folk revivalist trio from Greenwich Village Peter, Paul and Mary recorded the song and enjoyed much greater success with their version. Trini Lopez also recorded it a year later. Numerous other artists from around the world have recorded versions the song throughout the years. Between the Weavers' recording and that by Peter, Paul and Mary, the song has had such wide, inter-generational success that it's become part of the fabric of American folk music.
*****REVISED/REFORMATTED April 23, 2019 - SR****