The historical event that occurred on December 7, 1941, was the attack on Pearl Harbor by the Japanese military. This surprise military strike occurred during World War II, targeting the United States Pacific Fleet stationed at the naval base in Hawaii. The attack resulted in significant destruction, with numerous ships sunk or damaged and thousands of American service personnel killed or wounded. This event led to the United States formally entering the war against Japan and subsequently joining the Allied Powers. The attack marked a pivotal turning point in the conflict and significantly impacted the trajectory of the war.