Roosevelt calls it "a date which will live in infamy" and, the next day, the U.S. officially enters World War II, declaring war on Japan.
In a surprise wave of attacks on the U.S. naval base at Oahu Island, Hawaii's Pearl Harbor, Japan, aligned with the Axis, takes out America's Pacific fleet (the fleet's three aircraft carriers are not present during the attack). With approximately 2,400 U.S. troops killed and another 1,000 wounded, President Franklin D. Roosevelt calls it "a date which will live in infamy" and, the next day, the U.S. officially enters World War II, declaring war on Japan.