Hallock was ordained deacon on November 25, 1934, and priest on June 16, 1935, by Bishop
Benjamin F. P. Ivins. He was priest-in-charge of Holy Trinity Church in
Platteville, Wisconsin between 1935 and 1940. He also served as priest-in-charge of Kemper Memorial Church in
Darlington, Wisconsin, Trinity Church in
Mineral Point, Wisconsin, and St Michael and All Angels' Church in
Shullsburg, Wisconsin between 1938 and 1940. In 1940, he served in the Army during World War II, leaving active duty as a colonel in 1946. He was consequently awarded the
Legion of Merit. In 1946 he became rector of St John's Church in
Grand Haven, Michigan, while in 1949, he became rector of Grace Church in
Hinsdale, Illinois. ==Bishop==