Operation Cobra and the Great Offensive Sixty Days That Changed the Course of World War II

Prologue Six weeks had passed since Operation Overlord, the Allied invasion of Normandy that took place on "D-Day" -- June 6, 1944. On that day, for the first time since William of Normandy became William the Conqueror in 1066, a military force had successfully crossed the English Channel and secured a foothold on the opposing shore. Overlord was rightly heralded -- then as now -- as one of the greatest military achievements in the history of modern warfare.Four years earlier, in June 1940, Germany's then-invincible Wehrmacht had stunned the world by defeating and occupying France in a matter of weeks. During the four ensuing years, German military engineers had worked tirelessly on the northern and western coasts of France to create the Atlantic Wall, the most formidable network of fortifications ever constructed. Much of the reinforced concrete poured by the Germans during those four years still survives in the twenty-first century. It is so solid that it is not economically practical to dismantle it.The German idea was to build a wall that would make the Allies consider an invasion of northern France impractical. Adolf Hitler himself had such great confidence in the Atlantic Wall that he assuredly referred to his empire as Festung Europa -- Fortress Europe.The Anglo-American Allies, of course, had other ideas.The idea of a cross-channel invasion as the means to liberate France and defeat Germany had been agreed to in principle by President Franklin Delano Roosevelt and British Prime Minister Winston Churchill in April 1942, and it was at the Eureka Conference in November 1943 that the two Allied leaders gave the 1944 invasion priority over all other military operations that the Anglo-American Allies would undertake anywhere in Europe, the Mediterranean, or the Pacific.On December 7, 1943, two years to the day after the United States entered World War II, US Army Chief of Staff George Marshall informed General Dwight Eisenhower that he was to be the Supreme Allied Commander for history's biggest military operation.When Eisenhower arrived in England in mid-January 1944 to set up the Supreme Headquarters, Allied Expeditionary Force (SHAEF), American supplies had been flowing into the island nation for two years, but what had initially been a trickle now became a torrent. Nevertheless, a great deal of key materiel would not arrive until May.To insure the success of Overlord, Eisenhower had amassed the largest force of men and war machinery that would be committed to a single operation in the history of warfare.The 175,000 men of Operation Overlord would make the trip across the English Channel aboard more than 5,000 ships and landing craft supported by 6 battleships, 2 monitors, 22 cruisers, 93 destroyers, 250 mine sweepers, and 150 smaller fighting craft, not including motor torpedo boats and mine layers.Overhead, the British First Tactical Air Force and the American Eighth and Ninth Air Forces committed 5,000 fighters; 3,500 heavy bombers; 1,600 medium, light, and torpedo bombers; and 700 other combat aircraft. This was not to mention the 2,300 transports and 2,600 gliders that would carry paratroopers into battle.Overlord's landing zone would be a fifty-mile section of the Normandy coastline between the neck of the Cotentin Peninsula in the west and the mouth of the Orne River in the east. This region, in turn, had been divided into five zones or "beaches." The westernmost, Utah and Omaha, were assigned to General Omar Bradley's United States First Army, while the others -- Gold, Juno, and Sword -- were assigned to the British and Canadians of General Sir Miles Dempsey's British Second Army.The troops would come ashore across the beaches. Prior to these amphibious landings, under cover of darkness in the early morning hours of D-Day, paratroopers of the United States 82nd and 101st Airborne Divisions would land behind the line of German coastal defenYenne, Bill is the author of 'Operation Cobra and the Great Offensive Sixty Days That Changed the Course of World War II' with ISBN 9780743458825 and ISBN 0743458826.