Peter, Paul and Mary was an American folk music group formed in 1961, known for their harmonious vocals and socially conscious lyrics. The trio consisted of Peter Yarrow, Paul Stookey, and Mary Travers. They gained popularity during the folk music revival and became symbols of the 1960s protest movement. Their most famous songs include "Puff, the Magic Dragon" and "Leaving on a Jet Plane." The group was influential in promoting folk music and addressing social issues, such as civil rights and anti-war sentiments. They remained active until the late 2000s, leaving a lasting legacy in American music.