Howard Zinn, author of the popular book, A People's History of the United States, died on Wednesday in Santa Monica, California. He was 87. He suffered from a heart attack, according to the New York Times. In 1956, the iconic historian was offered the chairmanship of the History and Social Sciences Department at Spelman College. During the Civil Rights movement, Zinn pushed his students to request books from the segregated public libraries. The passionate activist also helped coordinate sit-ins at downtown cafeterias.