First recorded (as “The Hammer Song”) by The Weavers (1950).
Hit versions by Peter, Paul & Mary (US #10 1962), Trini Lopez (US #3 1963).
From the wiki: “‘If I Had a Hammer (The Hammer Song)’ was written by Pete Seeger and Lee Hays in 1949 in support of the progressive movement, and was first recorded by The Weavers in 1950. It was not particularly successful in commercial terms when it was first released.
“The song was first performed publicly by Pete Seeger and Lee Hays on June 3, 1949, at St. Nicholas Arena in New York City at a testimonial dinner for the leaders of the Communist Party of the United States. It was later part of the three songs Seeger played as the warm-up act for Paul Robeson’s September 4, 1949, concert near Peekskill, New York, which subsequently erupted into a riot.
“‘If I Had a Hammer’ went on to become a Top-10 hit for Peter, Paul and Mary in 1962 and, a year later, went to #3 when recorded by Trini Lopez.”