OVERLORD was a triumph of Allied cooperation and planning—and “D-Day” takes you inside the rooms where it happened. On the surface Anglo-American unity was the top priority. Yet behind the public face of Allied harmony lay a more conflicted reality. Years of disagreements, postponements, and sometime angry debate preceded the decision to undertake the great invasion. Churchill observed, “There is only one thing worse than fighting with allies, and that is fighting without them.” Understanding their differences makes the successful wartime collaboration in their “mighty endeavor” even more remarkable. Using the collections of the Franklin Roosevelt Presidential Library and the Churchill Archives Centre of Churchill College, Cambridge, this special exhibit tells the story of that collaboration and the friendship that sustained it.