The following post is by Ryan Moore, a cartographic specialist in the Geography and Map Division.
In the morning hours of December 7, 1941, 76 years ago today, the Japanese Imperial Navy launched a stunning and destructive attack on the American Pacific Fleet at Pearl Harbor. On that “date which will live in infamy,” as President Franklin D. Roosevelt remarked, hundreds of Japanese planes attacked in waves. Four American battleships were sunk and four others damaged. Among the battleships lost was the USS Arizona, which was destroyed by armor-piercing bombs that killed 1,177 crewman, accounting for nearly half of the total death toll of the attack on Pearl Harbor. Many cruisers, destroyers, and other ships were damaged along with land installations and aircraft. With a portion of the American Pacific Fleet left burning, the nation was shocked and outraged. That same day, Japanese forces attacked American bases in the Philippines, Guam, and Wake Island, and British bases in Malaya, Singapore, and Hong Kong.
Fortunately, for the United States, the defeat at Pearl Harbor was not fully a strategic one. The American aircraft carriers, which the Japanese intended to target, were at sea. Task Force Eight, headed by the USS Enterprise, was about two hundred miles west of Pearl Harbor. Task Force Twelve, led by the USS Lexington, was approximately 460 miles from Midway Island. The USS Saratoga was based at San Diego. Carriers were essential for protecting surface vessels, including mighty battleships, from air attack. No modern navy could be effective without them.
The Japanese plan was to temporarily paralyze the U.S. fleet while Japanese troops waged actions to seize and consolidate territory throughout Asia and Oceania. War soon followed. The United States recovered from the loss of ships and avenged the sailors, marines, and soldiers who were killed at Pearl Harbor. By 1945, the Japanese Empire was defeated and it surrendered September 2, which is referred to as V-J Day (“Victory over Japan Day”).
After the war ended, the U.S. Senate launched an inquiry into the Pearl Harbor attack. The eight senators involved explained that the investigation had been delayed until that point because the country had been at war. Previously, President Roosevelt ordered an investigation under the direction of the Supreme Court, which found the military base commanders at Pearl Harbor were ill-prepared. Rumors also circulated that President Roosevelt was determined to draw the nation into the war and had left Pearl Harbor unguarded in order to bait the Japanese into a war. The senators hoped to resolve the “contradictions and inconsistencies” of the preceding reports and information.
From November 1945 through May of 1946, the committee heard testimony from 44 people, including top level military commanders and diplomats. The hearing transcripts filled more than 5,000 printed pages and included some 14,000 pages of printed exhibits, including the map featured in this blog. It depicts the location of American warships at the time of the attack on Pearl Harbor. Stamped “Top Secret,” the map was declassified in 1946. The map’s purpose was to illustrate the location of American ships and the fleet’s overall readiness.
The senators’ investigation determined that “the ultimate responsibility for the attack and its results rests upon Japan, and the diplomatic policies and actions of the United States provided no justifiable provocation whatever for the attack by Japan on this Nation.” The report stated that “officers, both in Washington and Hawaii, were fully conscious of the danger from air attack.” The military commanders made “errors of judgment and not derelictions of duty.” The investigation roundly rejected the claim that President Roosevelt and top advisors “tricked, provoked, incited, cajoled, or coerced Japan” into attacking the United States in order to draw the nation into war.