In the 1919 election for adjutant general, Tillotson sought to reclaim the post he had held prior to the war. Johnson defeated Tillotson, and continued to serve as adjutant general. (Vermont's adjutant general is elected to a two-year term by the
Vermont General Assembly. At the time, elections were held in February of each odd-numbered year, and the term started in March.) Tillotson returned to the Army, and served until retiring as a colonel in 1938. As Adjutant General Johnson oversaw the construction of 12 new armories, modernization of the Vermont National Guard after World War I, and the Vermont National Guard's response to the
Flood of 1927. In 1924 Johnson graduated from the
United States Army War College, the first state adjutant general to do so. At the start of
World War II Johnson was appointed Vermont's federal
Director of Selective Service, responsible for ensuring that eligible men registered for the draft. He continued to serve until 1941, when he retired because of ill health and was succeeded by Murdock A. Campbell. His 24 years in the position make him Vermont's second longest-serving adjutant general, behind only the first holder of the post,
David Fay. Johnson was an active member of the Adjutants General Association of the United States (AGAUS) and served as its president. ==Death and burial==