Pearl Harbor Timeline


July, 1940 Trade Sanctions, Embargo

July 1940

United States imposed trade sanctions, then embargo, trying to slow Japan's military aggression


January - Possible Attack Communication

January, 1941

Admiral Yamamoto communicates with Japanese officers about Pearl Harbor attack.

February - Adm. Husband E. Kimmel

February, 1941

Admiral Husband E. Kimmel is takes over command of U. S. Pacific Fleet in Hawaii.

April - U. S. intellifence monitors Japan

April, 1941

United States intelligence officers monitor Japanese secret communications.

May - Japan discovers U. S. reading messages

May, 1941

Japanese Admiral Nomura informs his superiors that U. S. has been reading messages. Noone believed the code could be broken and was not changed.

July - Japan plans attach

July, 1941

Admiral Yamamoto trains military and plans for Pearl Harbor attack.

September - Bomb Plot

September 24, 1941

Bomb plot message from Japanese naval intellifence to Japan's consul in Honolulu requested locations of U. S. ships in Pearl Harbor.

November - Japanese diplomat in U. S.

November, 1941

Diplomat from Tokyo comes to Washington to seek a diplomatic solution. Japan wants the U.S. to agree to its Southern expansion in Asia. U. S. did not agree and Japan wa prepared for a war.

November 26 - Japan begins voyage to Hawaii

November 26, 1941

November 27 - War Warning from Washington

November 27, 1941

War Warning received from Washington informing of a Japanese attack with a possible American target in the Pacific.

Pearl Harbor Attack

December 6 & 7 - Message decoded

December 6, 1941

U. S. Intelligence decodes a meassage stating Sunday morning as a deadline for a Japanese attack. The message was received in Washington bur not forwarded to Pearl Harbor. The message arrived after the attack has started.

December 7, 1941 - 7:55 a.m. First Japanese attack

December 7, 1941

The first Japanese aircraft started attacking Pearl Harbor. Airfields and ships are attacked. The attack continued for 2 hours and 20 minutes. When over, more than 2,400 Americans died and 1,200 wounded. Eighteen ships were sunk or dmanged and over 300 aircraft were destroyed or damaged.

December 8, 1941 - Roosevelt addresses Congress

December 8, 1941

President Roosevelt asked Congress for a declaration of war on Japan, which he received.

December 16, 1941

December 16, 1941

Admiral Kimmel and General Short are relieved of their commands.