President Franklin Delano Roosevelt's "Day of Infamy" speech on December 8, 1941, marked the United States' declaration of war against Japan following the attack on Pearl Harbor. In his address to Congress, delivered just one day after the devastating events in Hawaii, Roosevelt declared that December 7th would forever be remembered as a date of infamy. The speech, given at 12:30 p.m., swiftly led to Congress passing a formal declaration of war, officially bringing the U.S. into World War II. This historic speech is recognized as one of the most impactful and memorable in American political history, setting the tone for the nation's involvement in the global conflict.