The United States launched its first air raid on Japan four months after the attack on Pearl Harbor. Sixteen B-25 Mitchell bombers were launched from the aircraft carrier USS Hornet on 18 April 1942 in what became known as the Doolittle Raid. While this first attack did minimal damage, it provided a great morale boost for the American public.
The United States would not begin large-scale attacks on the Japanese home islands until 1944. With the introduction of the B-29 Superfortress in 1944, the United States was able to launch long-range bombing missions from bases in China and the Mariana Islands.
In March 1945, Gen. Curtis LeMay began to shift the bombing campaign away from precision bombing, to focus on firebombing Japanese cities. On the night of 9 March 1945, Operation Meetinghouse was launched. The US deployed over 330 B-29s to target the Japanese capital of Tokyo. The raid caused a massive firestorm in the capital, destroying over 16 square miles of the city and killing over 80,000 Japanese civilians.
For the next six months, the US continued to launch devastating firebombing raids against Japanese cities. The Allied commanders had hoped this campaign would encourage the Japanese to surrender, but by August the Japanese remained steadfast in their refusal to end the war. On 6 August 1945, the US launched a nuclear attack on Hiroshima. It followed three days later with a second attack on Nagasaki. On 2 September, the Japanese formally surrendered to the Allies, bringing World War II to an end.