On December 7th, 1941, Japan launched a surprise attack on the United States of America by bombing the U.S. naval base at Pearl Harbor, Hawaii.

The first of nearly 200 Japanese planes began dropping bombs on Pearl Harbor just before 8:00 in the morning. Because Hawaii is located thousands of miles from Japan, U.S. military officials had doubted that the Japanese would attempt an attack there, leaving Pearl Harbor an open and inviting target.

The Japanese government appeared to be continuing negotiations with the United Sates in good faith. American intelligence, however, had decoded Japanese messages that made it clear that Japan was preparing to go to war against the United States. On November 27, American commanders at the Pearl Harbor naval base recieved a war warning from Washington D.C., but from Japan, officials doubted that Japan would attack Hawaii. 

The U.S. military's inability to interpret the information that they were receiving correctly left Pearl Harbor an open target. Japan's surprise attack on December 7, 1941, was devastating. Though the raid only lasted 75 minutes, eight battleships, three cruisers, three destroyers, and four other vessels were sunk or damaged. the attack destroyed over 180 aircraft and killed 2,403 Americans. Another 1,178 were injured.

While the attack on Pearl Harbor was a surprise, tensions between the U.S. and Japan had deteriorated over the decade, in particular with regards to Japan's expansion into China. 

The plan for attacking Pearl Harbor was to destroy the U.S.'s Pacific Fleet, a move which would give the Japanese time to carry out its plans to keep control of the Pacific without U.S. interference.

The shock of the attack without declaration of war enraged the American public and failed the nation to get behind a war many hoped to avoid.

At the beginning of President Franklin D. Roosevelt's speech to Congress requesting a declaration of war, he delivered this now famous line, "Yesterday, December 7th, 1941, a date which will live in infamy, the United States of America was suddenly and deliberately attacked by naval and air forces of the empire of Japan."

On December 8th, 1941, one day after the attack, the United States Congress declared war on japan, officially entering World War II.