FDR gave this speech on December 8th, 1941 in urgent response to the devastating attack on Pearl Harbor by the Japanese Air Force. Maybe his most memorable phrase described the day of the attack, December 7th, 1941, as "a date which will live in infamy" (grammar sticklers might wish he had used "that" instead of "which," but it sounded good and there's no changing it now).

While everyone was surprised by the attack and its effectiveness, FDR was more mentally prepared for something like it than much of the public. Shortly after giving the speech, the United States officially declared war on Japan, with only one vote between the two houses of Congress opposed to the declaration. A few days later, the U.S. declared war on Germany and Italy.

As an historical document with political and legal implications, FDR's "Pearl Harbor" speech basically supplanted the Lend-Lease entirely. Instead of the tiptoeing, verbose song-and-dance that makes up the context of Lend-Lease as a means of working around the sensitivities of isolationist sympathizers, "Infamy" was all about bringing the smackdown in the most overt way. The speech itself is now nearly as famous a declaration of war as the terrible acts of violence the sparked its pronouncement.