In the last week of July 1944, the Allies were still stuck in Norman hedgerow country, and they needed to break out because they were far behind schedule. Also, the Soviets were nearing Warsaw, and Churchill feared the post war ramifications of the Soviets invading Germany while the Allies were still stuck in France. The Allies fell back on good old American firepower and devised Operation Cobra.
On 25 July, the entire Eighth Air Force and British Bomber Command carpet bombed a narrow 6km portion of the front near St. Lo. After which the US VII Corps, including the US 1st Infantry Division, charged through. Unfortunately, of the 2000 bombers, 80 dropped their bombs short and caused serious friendly casualties including a US 3 star general (McNair), and disrupted the follow on attack. The bombers pulverized German defenses but the attacking troops soon encountered a situation that would have been very familiar to their fathers in World War One: the devastation was so great that the attackers couldn’t move or bring up supplies over the terrain fast enough before German reserves were brought in to defend the shell holed moonscape left behind by the bombing. Fortunately, most German reserves were tied down by companion British offensives. By August, the Germans were pushed out of the hedgerow country and the Americans were poised to breakout of Normandy.
On 1 August, Operation Fortitude, the deception to convince the Germans the Allies would land at Pas de Calais concluded when LTG George Patton’s 3rd Army was activated on the continent (The Germans were convinced Patton would lead the landings at Pas de Calais). By 4 August Patton had broken out of Normandy and was tearing ass across France…in the wrong direction. Patton broke out, but he did so by going west into Brittany and toward the Atlantic coast, not east towards Paris and Germany. It took another week or so for Patton to turn around and attack in the right direction.
Hitler, ignorant of the true situation, saw an “opportunity” to destroy Patton and ordered an offensive of 13 panzer divisions to seize Avaranches and cut off the 3rd Army from Normandy. Only four were able to participate and they didn’t get very far. On 9 August Montgomery launched Operation Bluecoat and then Operation Tractable to cut off this German attack that threatened to cut off Patton’s attack. Eventually, Gen Von Kluge called off the western offensive when it was obvious (to everyone except Hitler) his troops were driving further into a trap as Polish and Canadian tankers closed in from the north and Patton closed in from the south.
On 13 August, Von Kluge ordered the retreat expressly against Hitler’s wishes in order to save as many panzer troops before they were encircled in what would later be known as the Falaise Pocket. The Allies had broken out of Normandy, permanently. The race was on.