[1][2] Boster was born on September 14, 1920,[3] in Rio Grande, Ohio, United States.

In 1951 he served as the United States liaison officer to the Soviet and Eastern European delegations at the Japanese Peace Conference in San Francisco.

He also served as the staff assistant to Secretary of State John Foster Dulles.

From 1959 to 1962 he was the officer in charge of Soviet Union affairs in United States Embassy in Moscow.

He served in that position under Presidents Richard Nixon and Gerald Ford during the presidencies of Mohammad Mohammadullah, Sheikh Mujibur Rahman, Khondaker Mostaq Ahmad and Abu Sadat Mohammad Sayem till 1976, after which he served as the United States Ambassador to Guatemala.