What has been called, "The Longest Day", D-Day, the Allied invasion to liberate Western Europe from Nazi control took place on this day, June 6, 1944. My father was in the U.S. Cavalry during World War II and arrived in France after the battle of Normandy, but was later called up for the "Battle Of The Bulge".

Here's more about that fateful day, according to army.mil.com:

"June 6, 1944, 160,000 Allied troops landed along a 50-mile stretch of heavily-fortified French coastline to fight Nazi Germany on the beaches of Normandy, France. General Dwight D. Eisenhower called the operation a crusade in which “we will accept nothing less than full victory.” More than 5,000 Ships and 13,000 aircraft supported the D-Day invasion, and by day’s end on June 6, the Allies gained a foot- hold in Normandy. The D-Day cost was high -more than 9,000 Allied Soldiers were killed or wounded -- but more than 100,000 Soldiers began the march across Europe to defeat Hitler."

Watch this video from history.com for more about D-Day: