President Franklin Roosevelt said Dec. 7, 1941 -- the day Japanese forces bombed Pearl Harbor -- was a date that would "live in infamy."
If that date marked one of the darkest days in U.S. history, then June 6, 1944, will be remembered by many as the beginning -- the beginning of the end of World War II.
The seeds of a cross-channel invasion were actually planted in 1940 after Nazi forces had taken over France.
At the Quebec Conference in August 1943, British Prime Minister Winston Churchill and Roosevelt reaffirmed the plan to retake France, which was code-named Overlord.
Although Churchill acceded begrudgingly to the operation, historians note that the British still harbored persistent doubts about whether Overlord would succeed, according to the National Archives.
The decision to mount the invasion was cemented at the Teheran Conference in November and December 1943. Russian leader Joseph Stalin, on his first trip outside the Soviet Union since 1912, pressed Roosevelt and Churchill for details about the plan, particularly the identity of the supreme commander of Overlord.
Churchill and Roosevelt told Stalin that the invasion “would be possible” by Aug. 1, 1944, but that no decision had yet been made to name a supreme commander.
To this latter point, Stalin pointedly rejoined, “Then nothing will come of these operations. Who carries the moral and technical responsibility for this operation?”
Churchill and Roosevelt acknowledged the need to name the commander without further delay. Shortly after the conference ended, Roosevelt appointed Gen. Dwight David Eisenhower to that position.
By May 1944, 2,876,000 Allied troops were amassed in southern England. While awaiting deployment orders, they prepared for the assault by practicing with live ammunition.
The largest armada in history, made up of more than 4,000 American, British, and Canadian ships, lay in wait. More that 1,200 planes stood ready to deliver seasoned airborne troops behind enemy lines, to silence German ground resistance as best they could, and to dominate the skies of the impending battle theater.
Against a tense backdrop of uncertain weather forecasts, disagreements in strategy, and related timing dilemmas predicated on the need for optimal tidal conditions, Eisenhower decide before dawn on June 5 to proceed with Overlord.
Eisenhower prepared his printed Order of the Day for June 6, 1944, which he actually began drafting in February. The order was distributed to the 175,000-member expeditionary force on the eve of the invasion.
Later that same afternoon, he scribbled a note intended for release, accepting responsibility for the decision to launch the invasion and full blame should the effort to create a beachhead on the Normandy coast fail.
It said: "Our landings in the Cherbourg-Havre area have failed to gain a satisfactory foothold and I have withdrawn the troops. My decision to attack at this time and place was based upon the best information available. The troops, the air and the Navy did all that Bravery and devotion to duty could do. If any blame or fault attaches to the attempt it is mine alone."
Fortunately, Eisenhower never had a need to send out any failure message. From the brochure “Normandy, 6 June-24 July 1944,” prepared in the U.S. Army Center of Military History by William M. Hammond:
“A great invasion force stood off the Normandy coast of France as dawn broke on 6 June 1944: 9 battleships, 23 cruisers, 104 destroyers, and 71 large landing craft of various descriptions as well as troop transports, mine sweepers, and merchantmen-in all, nearly 5,000 ships of every type, the largest armada ever assembled.
"The naval bombardment that began at 0550 that morning detonated large minefields along the shoreline and destroyed a number of the enemy's defensive positions. To one correspondent, reporting from the deck of the cruiser HMS Hillary, it sounded like ‘the rhythmic beating of a gigantic drum’ all along the coast.
"In the hours following the bombardment, more than 100,000 fighting men swept ashore to begin one of the epic assaults of history, a ‘mighty endeavor,’ as President Franklin D. Roosevelt described it to the American people, ‘to preserve our civilization and to set free a suffering humanity.’"
"The attack had been long in coming. From the moment British forces had been forced to withdraw from France in 1940 in the face of an overwhelming German onslaught, planners had plotted a return to the Continent. Only in that way would the Allies be able to confront the enemy's power on the ground, liberate northwestern Europe, and put an end to the Nazi regime."
Though D-Day was bloody and painful, and near disastrous on Omaha Beach for the U.S. soldiers attacking there, it was a success. The costs were staggering, even on the first day. Allied casualties on the first day were at least 10,000, with 4,414 confirmed dead. The Germans lost 1,000 men. Civilian casualties on D-Day and D+1 are estimated at 3,000.
There would be many bloody, painful and uncertain days ahead in the months ahead before Germany surrendered on May 7, 1945.
D-Day was not the end. But it was the beginning of the end.