Lionel McGarr was born on March 5, 1904, in Yuma, Arizona. He entered the U.S. Military Academy at West Point on July 1, 1924, and was commissioned a 2d Lt of Infantry on June 9, 1928. He served as an Infantry Platoon Commander from 1928 to 1931; as a Post Exchange Officer, Commanding Officer of a Guard Detachment, and Commanding Officer of a Disciplinary Barracks from 1931 to 1934; as an Infantry Company Commander from 1934 to 1938; and as an Instructor with the Hawaiian National Guard from 1939 to 1941. His next assignment was as an Intelligence Officer from 1941 to 1942, followed by service as Executive Officer and then Commanding Officer of the 30th Infantry Regiment of the 3rd Infantry Division in North Africa, Italy, France, and Germany from July 1942 to June 1945. Col McGarr served as Assistant Commander of the 3rd Infantry Division in Germany from June 1945 to March 1946, and then as Post Executive Officer at Fort Myer, Virginia, from March to August 1946. He attended the National War College in Washington, D.C., from August 1946 to June 1947, and then served on the staff of the Director of Intelligence on the General Staff, Headquarters U.S. Army, in the Pentagon from June 1947 to August 1950. His next assignment was on the staff of U.S. Forces Austria from August 1950 to July 1952, followed by service as Assistant Commander of the 2nd Infantry Division in Korea from July 1952 to February 1953. Gen McGarr next served as Commanding General of the Prisoner of War Command in Korea from February to October 1953, and then as Commanding General of the 7th Infantry Division in Korea from October 1953 to May 1954. He then served as Commanding General of U.S. Army, Caribbean, and as Commanding General of the 23rd Infantry Division at Fort Amador, Panama Canal Zone, from July 1954 to June 1956, and as Commandant and Commanding General of Army Command and General Staff College at Fort Leavenworth, Kansas, from July 1956 to July 1960. Gen McGarr's final assignment was as Chief of the Military Assistance and Advisory Group in South Vietnam from September 1960 until his retirement from the Army on July 1, 1962. He died on November 3, 1988, and was buried at San Francisco National Cemetery in San Francisco, California.