The answer was the Operation Cobra

Map of the Operation Cobra — Map: U.S. Army, Public domain, via Wikimedia Commons.

Year: 1944
Where: Saint-Lô, Normandy, France, France
War: World War II
Sides: United States and United Kingdom vs Nazi Germany
Troops: about 144,000
Casualties: about 24,950

Operation Cobra was an offensive launched by the First United States Army under Lieutenant General Omar Bradley seven weeks after the D-Day landings, during the Normandy campaign of World War II. The intention was to take advantage of the distraction of the Germans by the sustained British and Canadian attacks around Caen, and thereby break through the German defenses that were penning in their forces, while the Germans were unbalanced. Once a corridor had been created, the First Army would then be able to advance into Brittany, rolling up the German flanks once free of the constraints of the bocage country.

From Wikipedia, under CC BY-SA.

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