By July 1940, during
World War II (although the United States was still neutral at this point), he was a
G-3 staff officer with
I Armored Corps. He served with the corps until July 1942, seven months after the American entry into the war, which occurred due to the
Japanese attack on Pearl Harbor on December 7, 1941. He was appointed to the
one-star general officer rank of
brigadier general on August 5, 1942, and was sent to
England in November. Soon afterwards he was sent to
Morocco in
North Africa to command
Combat Command 'B' (CCB) of the
2nd Armored Division. He later served as
chief of staff of the
II Corps, then
fighting in Tunisia, under the command of
Lieutenant General George S. Patton Jr., later replaced by
Major General Omar Bradley. , pictured here sometime in 1944. In April 1943, when the campaign in North Africa was coming to an end, he was promoted to the
two-star general officer rank of major general and a month later became
commanding general (CG) of the 2nd Armored Division, replacing Major General
Ernest N. Harmon. At the age of 47, Gaffey was one of the youngest division commanders in the U.S. Army at the time. He commanded the division in the
Allied invasion of Sicily (codenamed Operation Husky) in the summer of 1943 where, fighting in difficult mountainous terrain and operating in very hot weather, the division, advancing some 200 miles and facing light resistance, captured the
Sicilian capital of
Palermo along with thousands of Italian soldiers. The 2nd Armored Division, under Major General Gaffey, was sent to England later in the year to train and spearhead the
Allied invasion of Normandy (codenamed
Operation Overlord), scheduled for the following year. , 28th Division; Major General Gaffey, and Lieutenant Colonel Campbell W. Newman. Neustadt, Germany, May 18, 1945. In April 1944, handing over command of the 2nd Armored Division to Major General
Edward H. Brooks, he was designated chief of staff of the
Third Army, serving again under Lieutenant General George Patton. Gaffey served in this capacity through the
campaign in Western Europe, from the time the Third Army landed in France in July 1944 and played a major role in
Operation Cobra and the
Battle of the Falaise Gap, followed by the
Allied advance from Paris to the Rhine and the
Battle of Metz. In December 1944 he replaced Major General
John Shirley Wood as CG of the
4th Armored Division, which played a major role in the
Battle of the Bulge, helping to break the
siege of Bastogne. He remained in command of the division until March 1945, towards the end of the
war in Europe, when he became CG of the
XXIII Corps. He relinquished command of XXIII Corps in September, when the war ended due to the
surrender of Japan. For his services during the war he was twice awarded the
Army Distinguished Service Medal. ==Postwar==