Japan's surprise attack on Pearl Harbor took under two hours to pull the US into WWII

On the morning of 7 December 1941, Japanese aircraft launched a surprise attack on the US naval base at Pearl Harbor, Hawaii, sinking or damaging 19 ships and killing over 2,400 Americans in roughly 90 minutes. The US had been officially neutral in the war; the next day, Congress declared war on Japan with only one dissenting vote. Franklin D. Roosevelt called it 'a date which will live in infamy.'

— Wikipedia contributors, Attack on Pearl Harbor — 7 December 1941