What was the decoy that the Allies did prior to the invasion?

Answer 1

The Allies used no tricks to decoy the US into WW 2. The Japanese attacked the US at Pearl Harbor, Hawaiian Territory, on Sunday, December 7, 1941. Therefore, it was an enemy attack by an AXIS Power that brought the US into WW 2. No tricks, as per the casualties of December 7, 1941 could attest to. Richard V. Horrell WW2Connections.com

Answer 2

Prior to Operation Overlord, the invasion of Normandy, the Allies ran a deception operation to convince the Germans that the invasion was planned for Calais. The name of this was Operation Quicksilver.

The Allies were aware that the German High Command believed that a major cross Channel invasion required taking a seaport. The Germans did not believe that the Allies could provide enough supplies for the invasion across beaches. Since Calais is the narrowest point of the Channel, it was a logical choice.

Operation Quicksilver had several aspects. Thousand of dummy tanks and truck (both inflatable and wood and canvas) which were placed in fields in England opposite Calais. German recon planes were allowed to photograph them. General George Patton was placed in command of the fictional First U.S. Army Group and he made numerous public appearances around Ipswich and Maidstone to fool the Germans into thinking that a huge force was assembling there (in WWII an "army group" was somewhere from 500,000 to 1,500,000 men). The Signal Corps generated thousands of bogus radio messages each day from this area, that the Germans intercepted and interpreted as the routine communications of the First U.S. Army Group. In one of the most bizarre tricks, the corpse of a drowned British civilian was dressed in the uniform of a headquarters officer and put into the sea off the coast of neutral Portugal, they broadcast faked radio messages from a disabled airplane, the fake officer had a mapcase with maps detailing the invasion plan for Calais, it was arranged that the body and maps were found by German agents in Portugal.