It was a large operation. If you ever get a chance to visit the Normandy area, do it. Amazing place to see especially when the anniversary ceremonies are on going. That 200 yard beach looks much longer a low tide. Many of the bunkers are still present. And at Pointe Du Hoc, the massive craters from the shelling are still there!
It's worth pointing out the planned invasion of Japan was going to be even larger. Fortunately they dropped the bomb. If they hadn't, many of us wouldn't be here today. Casualties were estimated to be upwards of 280,000. And with all the divisions Japan was moving to the landing zones, we would've faced and almost a one to one ratio. Not good odds. The D Day Museum in New Orleans has a whole floor dedicated to the planned invasion of Japan. Also a great place to visit and appreciate what the greatest generation, both the men and women of that generation accomplished.