On June 3, 1958, Christenberry was sworn in as acting Postmaster of New York. He was recommended for the position by Senator Jacob Javits after his original choice, Samuel Roman, declined the position. On July 6, 1959, he was nominated by President Eisenhower for permanent status as postmaster. He was confirmed by the United States Senate on September 15, 1959. He resigned as Postmaster due to ill health effective June 17, 1966.
