In 1966, he received a bachelor's degree from Northwestern University. During his time at Northwestern, Green was deeply influenced by three seminal events of 1963: President John F. Kennedy's civil rights address on national television on June 11; the assassination of civil rights leader Medgar Evers later that same evening; Martin Luther King Jr.'s "I Have a Dream" speech at the March on Washington for Jobs and Freedom on August 28; and the assassination of President Kennedy on November 22. Green interned in the summer of 1965 and 1966 in the office of U.S. Senator from Illinois Paul Douglas.