Hickey was born in South Boston, Massachusetts on April 1, 1898, a son of Lawrence Hickey and Johanna T. Hickey. He graduated from South Boston High School in 1916. Hickey was a prominent high school athlete, and was a member of South Boston's football, basketball, and track teams. South Boston High School also participated in the Boston School Cadets program, which provided military training to the city's male high school students. Hickey served in 2nd Battalion, 5th Regiment and attained the rank of captain. His desire for a military career was well-known among friends and family, and Hickey enlisted as a private soon after his high school graduation. He was promoted to corporal in 1917 and served in the enlisted ranks until being chosen for officer training. In the summer and fall of 1917, Hickey attended officer training at the Citizens Military Training Camp at Plattsburgh Barracks, claiming an 1897 date of birth and 1915 high school graduation in order to meet the eligibility requirements. In November 1917, Hickey received a Reserve commission as a second lieutenant of Cavalry.
Hickey served in France during World War I as a platoon leader in the 341st and 7th Machine Gun Battalions. He participated in the St. Mihiel and Meuse-Argonne Offensives, was wounded, and received the Purple Heart.
Post-World War I
Hickey continued his military career after the war, remaining in Germany as a member of the Army of Occupation until February 1922. Later that year, he transferred to the Field Artillery. In 1926, he graduated from the Field Artillery Officer Course. In 1932, he was assigned to train and advise National Guard units in the I Corps area. In 1938, he graduated from the Command and General Staff College. From 1940 to 1942 Hickey was an instructor at the Command and General Staff College.
Hickey was assigned as chief of staff for U.S. Forces Austria in 1946. From 1950 to 1952 Hickey was commander of the 82nd Airborne Division. Hickey commanded the XVIII Airborne Corps from 1952 to 1953.
Korean War
From 1953 to 1954, General Hickey commanded the IX Corps, leading the organization during the end of its occupation of the Line MissouriMain Line of Resistance and subsequent withdrawal from combat at the end of the conflict.
Post-Korean War
In 1954, Hickey was appointed deputy commander of U.S. Forces Far East and promoted to lieutenant general. General Hickey again commanded the IX Corps from 1954 to 1955. In 1955, he was named commander of Third U.S. Army at Fort McPherson, where he remained until his 1958 retirement.
From 1958 to 1961, General Hickey was Staff Director for the National Security Council's Net Evaluation Subcommittee. The Net Evaluation Subcommittee was established by President Dwight Eisenhower, and was charged assessing the U.S.S.R's capacity to inflict damage on the United States and U.S. overseas installations, as well as monitoring for changes that would alter those capabilities.
