Howard Zinn's advocacy efforts were characterized by significant life events, including his experiences as a World War II bombardier and his activism during the Civil Rights Movement. He strongly opposed militarism and government oppression and later authored "A People's History of the United States," which emphasized the voices of marginalized communities. His commitment to justice was rooted in his personal history, including working as a teacher and consistently challenging traditional narratives in history. Zinn's experiences fostered a lifelong dedication to social change, civil rights, and grassroots activism, making him a prominent historian and advocate.