From Wikipedia, the free encyclopedia. Edmund Sixtus Muskie (March 28, 1914 – March 26, 1996) was an American statesman and political leader who served as the 58th United States Secretary of State under President Jimmy Carter from 1980 to 1981, a United States Senator from Maine from 1959 to 1980, the 64th Governor of Maine from 1955 to 1959, and a member of the Maine House of Representatives fr...