Strange things happen in wartime. We just became aware of this one in 2013. General Eisenhower approved the establishment of the 23rd Headquarters Special Troops unit. It was unlike any other Army operation. The 23rd was populated with artists, actors, designers, top flight radio operators, writers, camouflage engineers, audio engineers and support staff. There were about 1,100 men in the unit.
This unit was unique in the Army. It had approval from the highest levels, including President Roosevelt, who heartily approved. Winston Churchill had recommended it following British successes in the same area. They trained at various bases on the east coast, then headed for France. Their work would begin after the D-Day invasion.
The equipment of the 23rd included tanks (fake, inflatable rubber), vehicles (fake like the tanks), airplanes (see tanks), trucks carrying sound equipment and large sound-projecting loudspeakers on top, uniform insignia for many other units (but not their own), complete radio communications equipment, plenty of trucks and other vehicles (real) to move around in, and top-secret training in what to do with all this.
Their mission was large-scale hoaxing and deception. It was outdoor theater, with the stage being a land area where a U.S Army unit up to a division in size was positioned. The purpose was to deceive the German units into believing that they faced a large U.S. force just ahead. This an ancient tactic, millenia old. A campfXSXCire deception used in ancient China was used in the Civil War. The difference for the 23rd was the technology.
On at least 21 occasions the men of the 23rd impersonated and simulated U.S. Army units so successfully that the Germans were totally fooled. The deception allowed the real Army units to sneak away and attack the Germans at points where they were unprepared. The 23rd did their work so perfectly in March of 1945 that a U.S. infantry division crossed the Rhine into central Germany without encountering any organized resistance. The Germans were taken completely by surprise.
Because of its potential value in future wars, knowledge of the 23rd and its operations was classified for 50 years after the war, finally being released in 1996. That year was when Americans first learned about how important deception had been.