Over a career spanning more than five decades, many issues have moved Peter to commit his time and talent: equal rights, peace, the environment, gender equality, homelessness, hospice care, public broadcasting and education. Along with his singing partners, (Noel) Paul and Mary, Peter became deeply committed to the Civil Rights Movement, which brought them to Washington in 1963 to sing at the historic August 28, 1963 March On Washington led by Dr. Martin Luther King, Jr., as well as the equally historic Selma-Montgomery March in 1965. He co-organized with Cora Weiss, his friend and ally and a Nobel Peace Prize nominee, the famous 1969 “Celebration of Life,” a march and demonstration in Washington, DC attended by a half-million people who demanded an end to America’s military involvement in Vietnam.

Though much of Peter’s activism has been directed toward the social/political arena, Peter has also been active on behalf of more personal projects such as the Hospice Movement. He is a board member of the Connecticut Hospice, the first hospice established in the United States, where he periodically sings for patients and staff and a voice of media advocacy for over two decades. In 1996, Peter founded the “Save One Child” Fund, now centered at Roosevelt Hospital’s Institute of Neurology and Neurosurgery (INN) in New York City. Over the last 15 years, Save One Child has provided free interventional radiological and neuro-surgical treatment, saving the lives of over 200 children, all expenses paid.

Peter's gift for songwriting has produced some of Peter, Paul & Mary's most poignant songs, including “Puff, the Magic Dragon,” “Day is Done,” “Light One Candle,” and “The Great Mandala.” As a member of the renowned musical trio, he has earned many gold and platinum albums and has been awarded and nominated for numerous Grammys.

Peter has produced critically acclaimed films, including "You are What You Eat," as well as co-producing three CBS network animated television specials based on "Puff, the Magic Dragon,” for which he received an Emmy nomination.

Peter's achievements have led him to address what he considers to be perhaps his most meaningful and ambitious undertaking to date. In 1999, Peter launched an educational non-profit called Operation Respect: “Don’t Laugh At Me” based on his passionate belief that music can be a transformative tool for educating the ethical sensibilities of children. OR focuses on creating a positive, safe, respectful, bully-free school environment where students can grow and learn, free of torment and attacks by their peers. OR’s educational program called “Don’t Laugh At Me” is now incorporated in some fashion in an estimated 22,000 schools across America.