When FDR stood in front of Congress to address the nation following the attacks on Pearl Harbor, everyone was still in shock. Never in history had the U.S. been the victim of an unprovoked attack.

In a show of support that was quite a bit different from a year earlier, when FDR gave his "Great Arsenal of Democracy" speech, Americans wanted justice, and they were ready to go to war to get it.

This speech was significant for a number of reasons. Congress declared war less than an hour later, with only one person voting against it, and the audience was the largest in radio history. Plus, the speech emphasized FDR's role as the kind of leader American citizens could count on, and the perfect person to lead the U.S. and avenge those lost at Pearl Harbor.

FDR's speech acknowledged the tragedy, but also focused on the way the American spirit would persevere and win against the kind of enemy that would attack when nobody was looking. It also put a firm end to any doubt that the U.S. could or would stay out of the fighting in Europe and the Pacific.

Within days, millions of young men enlisted in the military, and production of weapons and other war materials increased even more. (Thanks, Rosie the Riveter.)