After the attack on Pearl Harbor on December 7, 1941, several critical events and consequences unfolded:

• The attack caused severe damage to the U.S. Pacific Fleet, with 19 ships damaged or sunk, including battleships like the USS Arizona and USS Oklahoma, and the loss of 2,403 American lives, including military personnel and civilians

• The day after the attack, President Franklin D. Roosevelt addressed a joint session of Congress, calling December 7 "a date which will live in infamy." Within an hour, Congress declared war on Japan, officially bringing the United States into World War II

• Following the U.S. declaration of war, Germany and Italy declared war on the United States on December 11, 1941, expanding the conflict to the European theater

• The attack galvanized American public opinion, ending isolationist policies and uniting the nation for total war. The U.S. rapidly mobilized its military and converted its economy to a war footing, increasing military personnel and production

• Anti-Japanese sentiment surged, leading to the internment of approximately 120,000 Japanese Americans, as well as thousands of German and Italian Americans, under suspicion of espionage

• The damaged U.S. battleships were eventually salvaged and repaired to join the war effort across the Pacific

• The attack also triggered broader military actions by Japan in the Pacific, including assaults on Malaya, Hong Kong, and the Philippines, marking the start of a wider Pacific War

• The attack had profound social impacts in the U.S., including increased roles for women in the workforce as men went off to fight, and widespread rationing and civil defense measures in Hawaii

In summary, the attack on Pearl Harbor resulted in the United States' entry into World War II, a shift from isolationism to active global engagement, significant military mobilization, and deep social and political changes at home