One of the biggest questions of the Second World War is, how the amphibious invasion
             of Normandy, France on June 6, 1944, was one of the major turning points of World War
             II? The greatest factors that made the amphibious invasion of Normandy, or better known
             as D-Day, successful were the planning ahead, the strategies used to trick the enemy as a
             result of great leadership, and the invasion itself with how the allies brought fresh troops
             over constantly to overwhelm the German army. The result of Operation Overlord being
             successful was a major turning point in the war and started the allies momentum towards
             winning back Europe from axis powers. Not only was D-Day one of the greatest
             invasions in history, but also one of the greatest gambles in history.
             The plan of the allied invasion was first introduced in January of 1943 by the United
             States at the Casablanca Conference with the other allied nations. The US's proposal
             received enough votes , but still only set up a combined planning staff. The plan,
             however, was not accepted until August 1943 at the Quebec Conference in Canada. The
             staff in charge of planning the invasion named this "Operation Overlord". Sir Allen
             Brook, a British Chief, was reluctant to realize how important an advanced plan of attack
             was. He could not understand why the US needed to prepare so far in advance. He called
             the US , "rigid and inflexible"(Miller 16), not realizing that the US was doing a terrific
             job in procurement, ship building, training troops, and in preparing the supplies necessary
             to place one and a half million troops in Normandy. Most of the preparations that made
             D-Day possible was led by US General Dwight D. Eisenhower. Originally General
             George C. Marshall was passionately pursuing to lead this operation but US president
             Franklin D. Roosevelt said that he could not spare such an important general. Marshall
             was sad yet h...