[3] In 1959, he served as the chargé d'affaires of the embassy in La Paz, Bolivia,[5] where he was awarded by the State Department for supervising the destruction of confidential files while anti-American forces attacked the mission on March 4, 1959.

[7] On October 7, 1967, the Ecuadorian government requested Coerr to be recalled from his mission,[7] accusing him of criticizing President Otto Arosemena.

These accusations came after a speech in support of the Alliance for Progress he gave at the Colegio Americano in Quito, which quoted numerous remarks made by Arosemena.

This came after Arosemena refused to sign the presidential declaration at the American Summit in Punta del Este that previous April, desiring more aid for Latin America and criticizing the Alliance for Progress.

[7] Following his expulsion, journalist Drew Pearson described him as "doing one of the best jobs of the many highly qualified men the State Department has sent lately to Latin America," while a Washington Post editorial described him as an "experienced practitioner of enlightened hemispheric diplomacy.

[3] Coerr died on October 5, 1996, at a hospital in Ajijic, Mexico, where he and his wife had lived for the past three months, due to complications of Parkinson's disease.