<P> Following the attack on Pearl Harbor , President Roosevelt officially pronounced 7 December 1941 , as `` a date which will live in infamy '' and asked for a declaration of war on Japan before a joint session of Congress on 8 December 1941 . The motion passed with only one vote against it , in both chambers . Just three days later , on 11 December 1941 Adolf Hitler declared war on the United States , and had already remarked on the evening of the date of the Japanese attack that `` We ca n't lose the war at all . We now have an ally which has never been conquered in 3,000 years '' . </P>
<P> Following the attack on Pearl Harbor , President Roosevelt officially pronounced 7 December 1941 , as `` a date which will live in infamy '' and asked for a declaration of war on Japan before a joint session of Congress on 8 December 1941 . The motion passed with only one vote against it , in both chambers . Just three days later , on 11 December 1941 Adolf Hitler declared war on the United States , and had already remarked on the evening of the date of the Japanese attack that `` We ca n't lose the war at all . We now have an ally which has never been conquered in 3,000 years '' . </P>
when did the united states officially entered ww2
when did the united states officially entered ww2
8 December 1941
8 December 1941