Helen Anderson

On October 28, 1949, Helen Anderson became the first woman ambassador, appointed by President Harry Truman to be Ambassador to Denmark. She was later appointed by Kennedy to be ambassador to Bulgaria (1962–1964). Thus, Anderson became the first American woman to represent the United States in a country allied with the Soviet Union.
After her retirement from these posts, President Johnson appointed Anderson to the United Nations Trusteeship Council and a year later she served on the United Nations Committee for Decolonization.