The way the Americans reacted when the United States entered WWII was Millions volunteered to serve in the US armed forces or were drafted to fight in the war.
When the Japanese bombed Pearl Habor, it led to a great deal of anger and patriotrism in the minds of Americans.
The nationalistic feeling was so strong that when the U.S. entered WWII, millions volunteered and others were then drafted to go fight against fascism and authoritarianism in WWII.
Find out more on the attack on Pearl Harbor at https://brainly.com/question/860420.