As a result of mobilization the Third Army took on the role of training some of the huge numbers of recruits that the draft was bringing into the United States Armed Forces.
Lieutenant General Walter Krueger, later to gain fame for his command of Sixth Army during operations in the Pacific, commanded Third Army from May 1941 until February 1943.
Under his leadership, the basis of the Army's later success as a combat formation was laid.
Krueger was succeeded by Lieutenant General Courtney Hodges who led the Army for the rest of 1943.
The news that many had expected came in December 1943 and the Third Army was shipped from the United States to the United Kingdom.

Third Army did not take part in the initial stages of Operation Overlord.
However, when it did take the field, it was led by George S. Patton.
When Third Army was moved to France, it was just after formations under the command of Omar Bradley had achieved the breakout from Normandy.
Third Army followed up on that success and began a great dash across France, ultimately out-running its supply lines and halting it near the German border.

After a period of consolidation, Third Army was ready to go on the offensive again.
However, the Germans then launched their last great offensive of the war – the Battle of the Bulge.
This battle was an attempt to repeat the decisive breakthrough of 1940.
However, in 1944, the Germans were doomed to failure.
Their own logistical problems surfaced, and they ground to a halt.
Nevertheless, they had broken the U.S. front, and it took a great effort to reduce the resulting salient.
In one of the great moves of the war, Patton heeded the advice of his Intelligence Officer, Oscar Koch, and planned to aid First Army if required.
When the German offensive commenced, Patton was prepared to turn Third Army's axis of advance  ninety degrees and advance north to the southern flank of the German forces.
The German salient was reduced by the end of January 1945, and the remainder of the process of closing up to the Rhine could be completed.
Some vicious fighting took place, but by April there was but one great natural barrier between Third Army and the heart of Germany.
Unlike in 1918, the crossing of the Rhine was opposed.
However, the bridgehead was won, and Third Army embarked on another great eastward dash.
It reached Austria and in May liberated the Mauthausen-Gusen concentration camps complex.
Its forces ended up in Czechoslovakia, the furthest east of any American units.

The Third Army After Action of May 1945 states that the Third Army captured 765,483 prisoners of war, with an additional 515,205 of the enemy already held in corps and divisional level POW cages processed between 9 May and 13 May 1945, for a total of 1,280,688 POWs, and that, additionally, Third Army forces killed 144,500 enemy soldiers and wounded 386,200, for a total of 1,811,388 in enemy losses.
Fuller's review of Third Army records differs only in the number of enemy killed and wounded, stating that between 1 August 1944 and 9 May 1945, 47,500 of the enemy were killed, 115,700 wounded, and 1,280,688 captured.
Fuller's combined total of enemy losses is 1,443,888 enemy killed, wounded, or captured by the Third Army.
The Third Army suffered 16,596 killed, 96,241 wounded, and 26,809 missing in action for a total of 139,646 casualties according to the aforementioned After Action Report of May 1945.
According to Fuller, the Third Army lost 27,104 killed and 86,267 wounded.
There were 18,957 injuries of all kinds and 28,237 men listed as missing in action.
Including 127 men captured by the enemy, total casualties of the Third Army were 160,692 in 281 continuous days of operations.
Fuller points out that the ratio of German troop deaths to American deaths in the Third Army operating area was 1.75:1.
As a result of mobilization the Third Army took on the role of training some of the huge numbers of recruits that the draft was bringing into the United States Armed Forces. Lieutenant General Walter Krueger, later to gain fame for his command of Sixth Army during operations in the Pacific, commanded Third Army from May 1941 until February 1943. Under his leadership, the basis of the Army's later success as a combat formation was laid. Krueger was succeeded by Lieutenant General Courtney Hodges who led the Army for the rest of 1943. The news that many had expected came in December 1943 and the Third Army was shipped from the United States to the United Kingdom.
Third Army did not take part in the initial stages of Operation Overlord. However, when it did take the field, it was led by George S. Patton. When Third Army was moved to France, it was just after formations under the command of Omar Bradley had achieved the breakout from Normandy. Third Army followed up on that success and began a great dash across France, ultimately out-running its supply lines and halting it near the German border. 
After a period of consolidation, Third Army was ready to go on the offensive again. However, the Germans then launched their last great offensive of the war – the Battle of the Bulge. This battle was an attempt to repeat the decisive breakthrough of 1940. However, in 1944, the Germans were doomed to failure. Their own logistical problems surfaced, and they ground to a halt. Nevertheless, they had broken the U.S. front, and it took a great effort to reduce the resulting salient. In one of the great moves of the war, Patton heeded the advice of his Intelligence Officer, Oscar Koch, and planned to aid First Army if required. When the German offensive commenced, Patton was prepared to turn Third Army's axis of advance  ninety degrees and advance north to the southern flank of the German forces. The German salient was reduced by the end of January 1945, and the remainder of the process of closing up to the Rhine could be completed. Some vicious fighting took place, but by April there was but one great natural barrier between Third Army and the heart of Germany. Unlike in 1918, the crossing of the Rhine was opposed. However, the bridgehead was won, and Third Army embarked on another great eastward dash. It reached Austria and in May liberated the Mauthausen-Gusen concentration camps complex. Its forces ended up in Czechoslovakia, the furthest east of any American units.
The Third Army After Action of May 1945 states that the Third Army captured 765,483 prisoners of war, with an additional 515,205 of the enemy already held in corps and divisional level POW cages processed between 9 May and 13 May 1945, for a total of 1,280,688 POWs, and that, additionally, Third Army forces killed 144,500 enemy soldiers and wounded 386,200, for a total of 1,811,388 in enemy losses. Fuller's review of Third Army records differs only in the number of enemy killed and wounded, stating that between 1 August 1944 and 9 May 1945, 47,500 of the enemy were killed, 115,700 wounded, and 1,280,688 captured. Fuller's combined total of enemy losses is 1,443,888 enemy killed, wounded, or captured by the Third Army. The Third Army suffered 16,596 killed, 96,241 wounded, and 26,809 missing in action for a total of 139,646 casualties according to the aforementioned After Action Report of May 1945. According to Fuller, the Third Army lost 27,104 killed and 86,267 wounded. There were 18,957 injuries of all kinds and 28,237 men listed as missing in action. Including 127 men captured by the enemy, total casualties of the Third Army were 160,692 in 281 continuous days of operations. Fuller points out that the ratio of German troop deaths to American deaths in the Third Army operating area was 1.75:1.
United States Army Central