Howard Zinn was motivated by a desire to challenge the traditional narratives of American history that often marginalized the voices of ordinary people. His experiences as a soldier in World War II and his exposure to social justice movements spurred his commitment to documenting histories of the oppressed. His seminal work, "A People's History of the United States," aimed to provide an alternative perspective that emphasized grassroots activism and the struggles of working-class individuals. Zinn sought to empower readers by presenting history as a collective effort, encouraging them to acknowledge their potential for change and activism.