What happened December 1941AD in United States of America

On the morning of December 7, 1941, the Japanese struck the U.S. naval base at Pearl Harbor with a surprise attack, knocking out the main American battleship fleet and killing 2,403 American servicemen and civilians.

On 7 December 1941, Japan attacked the American fleet based at Pearl Harbor, Hawaii. Four days later, Hitler declared war against the United States.

Following the attack on Pearl Harbor, the United States declared war against Japan, and within days China joined the Allies in formal declaration of war against Japan, Germany and Italy.

On 7 December 1941 (8 December in Asian time zones), Japan attacked Pearl Harbor. The attack on Pearl Harbor a surprise military strike by the Imperial Navy Air Service upon the United States against naval base at Pearl Harbor.

On December 8 (December 7 in Hawaii), 1941, in simultaneous attacks, Japanese forces struck at the Hong Kong Garrison, the US Fleet in Pearl Harbor and in the Philippines, and began the invasion of Malaya.

Roosevelt signed declaration of war against Japan on December 8

On December 8, 1941 (9 December in Asian time zones), the United States Congress declared war on the Empire of Japan in response to that country's surprise attack on Pearl Harbor the prior day.

On December 11, 1941, Hitler and Mussolini declared war on the United States, which responded in kind.

On December 11, 1941, the United States Congress declared war upon Germany, hours after Germany declared war on the United States after the attack on Pearl Harbor by the Empire of Japan.

On December 26, 1941, President Franklin D. Roosevelt signed a joint resolution of Congress changing the national Thanksgiving Day to the fourth Thursday in November.

The text of the "Declaration by United Nations" was drafted at the White House on 29 December 1941, by President Franklin D. Roosevelt, Prime Minister Winston Churchill, and Roosevelt aide Harry Hopkins. It incorporated Soviet suggestions but left no role for France. "Four Policemen" was coined to refer to four major Allied countries, the United States, the United Kingdom, the Soviet Union, and the Republic of China, which emerged in the Declaration by the United Nations.