On June 6, 1944, more than 160,000 Allied troops, including 73,000 Americans, landed along a 50-mile stretch of heavily fortified, German occupied, French coastline. U.S. Gen. Dwight D. Eisenhower, who was chain-smoking 6 packs of unfiltered cigarettes a day, by then, referred to the operation as a great crusade in which “we will accept nothing but full victory.”
Eisenhower had sole authority to either launch Operation Overlord...or scrap it. Eisenhower knew that it could be a turning point in the war, in either direction. He was fully prepared for the invasion to go down in history as a defeat that could make Custer's Last Stand look.like a victory. He was prepared to own the loss, should it go badly for the allies.
To see this, is to understand just how huge and chaotic the invasion really was: