Having been involved with the Democratic Party since she was first able to vote, for Franklin D. Roosevelt, in 1968 Butterworth became chair of the presidential campaign for Eugene McCarthy for Connecticut and served that year as a delegate to the Democratic National Convention. Opposed to the Vietnam War, she attended peace rallies and in 1971, Butterworth, as a member of the American Friends Service Committee, traveled with 169 delegates to Paris to discuss terms to attain peace to end the war. A committed pacifist, she wanted an immediate end to the war, but after the conference felt that if the United States Government did not initiate a peace plan, with a scheduled withdrawal, the conflict would be prolonged. For decades Butterworth protested every Saturday, in West Hartford Center, against war, including those in Nicaragua, Iran and Iraq, as well as in opposition to nuclear arms. She also served on the national board of the Committee for a Sane Nuclear Policy, known simply as SANE.