He was air deputy to the Supreme Allied Commander Europe, at SHAPE Headquarters from 1958 until he retired in 1961, but on later that year he was recalled to active duty to become director of the National Security Council's Net Evaluation Subcommittee Staff at the Pentagon. He finally retired in 1965. Johnson was born in Columbia, Missouri, on 13 September 1904. He had an older brother, a younger brother, and a sister. In 1919, the family moved to Moline, Kansas, where he went to high school. He played on the high school football team as a halfback, and was vice president of his senior class. After graduation, he worked in the family's bank. Johnson entered the United States Military Academy at West Point, New York, on 1 July 1922, and graduated 60th out of 152 graduates in the class of 1926 on 12 June 1926. In his final year , he was the First Sergeant of Company C. He was commissioned a second lieutenant in the infantry on 12 June 1926, and was posted to the 17th Infantry at Fort Crook, Nebraska, on 12 September 1926. He volunteered for service in United States Army Air Corps, and on 1 March 1929 he reported to the Air Corps Primary Flying School at Brooks Field, Texas, as a student officer. He married Lucille Taylor before completion of flight training. They had two daughters, Sue and Sarah. He was next sent to Kelly Field, Texas, for further training with the Observation Section from 15 October 1929 to 28 February 1930. On 1 March 1930, Johnson joined the 5th Observation Squadron at Mitchell Field, New York, as its adjutant and engineering officer, and was promoted to first lieutenant on 1 December 1931. On 15 June 1932 he joined the 2d Observation Squadron at Nichols Field in the Philippines. He returned to the United States in July 1935, and on 30 July 1935 he entered the California Institute of Technology, from which he received a master of science degree in meteorology on 1 July 1936. He was promoted to captain on 13 June 1936. He was then posted to Barksdale Field, Louisiana, as operations officer until 1 July 1937, when he became commander of the 3rd Weather Squadron, and was a student at the Air Corps Tactical School from 5 June to 25 August 1939. Johnson was operations officer of the 3d Bombardment Group at Barksdale Field from 15 July 1940 to 12 September 1940, and then its weather officer until 27 December 1940. The group moved to Savannah Army Air Base on 6 October 1940, and he was promoted to major on 16 November 1940.