On June 6, 1944, more than 156,000 American, British and Canadian troops stormed 50 miles of Normandy’s fiercely defended beaches in northern France in an operation that proved to be a critical turning point in World War II.

Allied leaders Franklin D. Roosevelt and Winston Churchill knew from the start of the war that a massive invasion of mainland Europe would be critical to relieve pressure from the Soviet army fighting the Nazis in the east.

Since Operation Overlord was launched from England, the U.S. military had to ship 7 million tons of supplies to the staging area, including 450,000 tons of ammunition. Here, ammunition is shown in the town square of Morten-in-Marsh, England ahead of the invasion.

The D-Day invasion began in the pre-dawn hours of June 6 with thousands of paratroopers landing inland on the Utah and Sword beaches in an attempt to cut off exits and destroy bridges to slow Nazi reinforcements.

U.S. Army infantry men approaching Omaha Beach, Normandy, France on June 6, 1944. The first waves of American fighters were cut down in droves by German machine gun fire as they scrambled across the mine-riddled beach.

At Omaha Beach, U.S. forces persisted through the day-long slog, pushing forward to a fortified seawall and then up steep bluffs to take out the Nazi artillery posts by nightfall. Shown, wounded U.S. soldiers lean against chalk cliffs after storming Omaha Beach.

Anticipating an Allied invasion somewhere along the French coast, German forces had completed construction of the “Atlantic Wall,” a 2,400-mile line of bunkers, landmines and beach and water obstacles. Here, a land mine is blown up by Allied engineers.

Shown are massive landings at Omaha Beach after it was secured by U.S. troops. Barrage balloons keep watch overhead for German aircraft while scores of ships unload men and materials. D-Day was the largest amphibious invasion in military history. Less than a year later, on May 7, 1945, Germany would surrender.