James Devereux was born on February 20, 1903, in Cabana, Cuba, while his father was stationed there as an Army surgeon. He enlisted in the U.S. Marine Corps on July 31, 1923, and completed basic training at Marine Base Paris Island, South Carolina, in October 1923. Cpl Devereux remained at Parris Island for additional training from October 1923 to May 1924, and then served with Marine Barracks, Washington, D.C., from June to July 1924. He was then selected for commissioning in the U.S. Marine Corps and attended Officer Candidate training at Marine Barracks, Washington, D.C., from July 1924 until he was commissioned a 2d Lt in the Marine Corps on February 19, 1925. Lt Devereux served at the Marine Barracks, Norfolk Navy Yard, Virginia, from February to July 1925, followed by the Basic School at Marine Barracks, Philadelphia Navy Yard, Pennsylvania, from August to December 1925. His next assignment was as a Company Officer with the 43rd Company, 5th Marine Regiment, at Marine Barracks, Quantico, Virginia, from January 1926 to July 1927, and during this time he served with the 23rd Company, 1st Battalion, 5th Marine Regiment at Guantanamo Bay, Cuba, from March to September 1926, and in the Nicaraguan Campaign from March to July 1927. Lt Devereux then served as a Detachment Officer with the Marine Corps Detachment aboard the battleship USS Utah (BB-31) from August 1927 to April 1929, and during this time he again participated in the Second Nicaraguan Campaign with the 77th Company, 2nd Battalion, 5th Marine Regiment from March 1928 to January 1929. His next assignment was as Post Remount Officer and Battalion Adjutant at Marine Barracks, Quantico, Virginia, from April 1929 to March 1930, followed by service as Officer in Charge of the Mounted Detachment with the Marine Detachment American Legation in Peiping, China, from June 1930 to September 1932. He served as Assistant Provost Marshall at Brooklyn, New York, from December 1932 to March 1933, and then attended Battalion Officer's Artillery School from March to June 1933. His next assignment was with Headquarters & Service Battery, 1st Battalion, 10th Marine Regiment at Quantico from June to September 1933, and he then attended the Coast Artillery School at Fort Monroe, Virginia, from September 1933 to June 1934. Capt Devereux served as Battery Executive Officer with Headquarters & Service Battery, 1st Battalion, 10th Marine Regiment at Marine Barracks, Quantico, from June to November 1934, followed by service as an instructor in the Small Wars Section at the Marine Corps Schools at Quantico from November 1934 to June 1936. His next assignment was as an instructor, senior instructor, and detachment commander with the Fleet Machine Guns School aboard the battleship USS Utah (BB-31) from June 1936 to June 1938, and then as a Battery Commander and Battalion Executive Officer with the 2nd Anti-Aircraft Artillery Battalion, 2nd Brigade, Fleet Marine Force at MCB San Diego, California, from June 1938 to December 1939. His next assignment was as Commanding Officer of the Anti-Aircraft Artillery Battery Company at MCB San Diego from December 1939 to March 1940, followed by service as Battalion Executive Officer and Reconnaissance Officer with 2nd Defense Battalion at MCB San Diego from March to July 1940. Maj Devereux served as Executive Officer of Headquarters & Service Battery, 1st Defense Battalion at MCB San Diego from July 1940 to February 1941, and then as Executive Officer of 1st Defense Battalion in Hawaii from February to August 1941. Maj Devereux then deployed to Wake Island with the 1st Defense Battalion, and fought the Japanese in the Battle of Wake Island from December 8, 1941, until he was forced to surrender to the Japanese on December 23, 1941. Col Devereux was held as a Prisoner of War for the next 1,361 days at Japanese POW camps in Shanghai and Peking, China, in Fusan, Korea, and at Hokkaido, Japan, before being repatriated on September 13, 1945. He was briefly hospitalized to recover from his injuries at the Naval Hospital in Bethesda, Maryland, and then was on rehabilitation leave from October 1945 to January 1946. His next assignment was at Marine Barracks, Quantico, where he served on temporary duty with Headquarters Marine Corps in Washington, D.C., as a Member of the General Court Martial Board, and as a Recruiting Officer, from January to September 1946. Col Devereux attended the Senior Course at the Amphibious Warfare School at MCS Quantico from October 1946 to May 1947, and then served as Commander of the 6th Marine Regiment, 1st Marine Division at Camp Pendleton, California, from July to October 1947. His next assignment was as Commander of Headquarters and Service Battalion, 1st Marine Division at Camp Pendleton from October 1947 until he was retired from the Marine Corps as a Brigadier General on August 1, 1948. After retiring from the Marine Corps he was elected to the U.S. Congress for Maryland's 2nd Congressional District and served from January 3, 1951, to January 3, 1959. James Devereux died on August 5, 1988, and was buried at Arlington National Cemetery.

His Navy Cross Citation reads:

The President of the United States of America takes pleasure in presenting the Navy Cross to Major James Patrick Sinnott Devereux, United States Marine Corps, for distinguished and heroic conduct in the line of his profession, as Commanding Officer of the First Marine Defense Battalion, Naval Air Station, Wake Island. Major Devereux was responsible for directing defenses of that post during the Japanese siege from 7 through December 22, 1941, against impossible odds. Major Devereux's inspiring leadership and the valiant devotion to duty of his command contributed in large measure to the outstanding success of these vital missions and reflect great credit upon the United States Naval Service.