Attack on Pearl Harbor

Learn about this historic event that caused the United States to enter World War II.

Sunday, December 7, 1941, was supposed to be a day of rest for the military soldiers at Hawaii’s Pearl Harbor naval base on the island of Oahu. But at 7:55 a.m., Japanese fighter planes zoomed in without warning and attacked the United States Pacific fleet, or naval vessels, moored in the harbor. Thousands of lives would be lost that day.

It was, as then President Franklin Delano Roosevelt would call it, "a date which will live in infamy."

THE PLAN

The sudden attack in Hawaii—at the time a territory of the United States, not a state—might have taken many by surprise, but the Japanese had been planning the operation for months.

Admiral Isoroku Yamamoto, commander in chief of the Japanese naval forces and architect of the Pearl Harbor attack, didn’t want a fight with America. But much of Europe and Asia, including Japan, were involved in World War II at the time. Yamamoto wanted to take over certain countries in southeastern Asia and use their oil to help fuel Japan’s military vehicles and naval fleet.

But because the U.S. base in Hawaii was relatively close to these countries, the Japanese worried that the United States would send soldiers from Pearl Harbor to defend the nations if they were attacked. By destroying the U.S. military presence in the region, the countries Japan wanted to target would be left vulnerable. So Yamamoto decided to move forward with a surprise attack on the U.S. fleet in Hawaii.

So on November 26, 1941, 31 warships carrying fighter planes and bombers slipped from Japan into the North Pacific. They moved silently until they closed in on the Hawaiian Islands. A small Japanese plane made a loop around the target and radioed back: “Pearl Harbor sleeps.”

THE ATTACK

At dawn on December 7, 350 planes launched in two waves from Japan’s ships. The bombers dropped bombs on American warships below, while the fighter planes targeted the U.S. aircraft on the ground so they couldn’t fight back.

Following both attacks, 19 U.S. naval vessels were sunk or damaged; 188 aircraft were destroyed. In all, 2,280 servicemen and women were killed, 1,109 were wounded. Sixty-eight civilians—people who are not in the military—also lost their lives. The attack lasted just under two hours.

THE AFTERMATH

Repair crews went to work on the ships. Except for the U.S.S. Arizona, Utah, and Oklahoma, every damaged ship returned to sea.

The day after the attack, the United States declared war on Japan, officially entering World War II. In the nearly four years that followed, the U.S. Navy sank all of the Japanese aircraft carriers, battleships, and cruisers that participated in the Pearl Harbor attack.

The United States and its allies—Britain, France, and Russia, among other countries—eventually won the war, defeating Japan and its allies, Germany and Italy.

Today visitors can tour the Pearl Harbor National Monument, built on the water above the wreckage of the U.S.S. Arizona, one of the eight battleships attacked and damaged during the fight. From there you can still glimpse at the remains of the sunken ship 40 feet below the water, a memorial to the brave people who fought in this important battle.

TEXT ADAPTED FROM PEARL HARBOR: A RETURN TO THE DAY OF INFAMY, OIL AND HONOR AT PEARL HARBOR, AND NATIONAL GEOGRAPHIC CONCISE HISTORY OF THE WORLD: AN ILLUSTRATED TIMELINE