The U.S. Naval War College has released a trove of World War II information by posting online the operational diary kept by Adm. Chester W. Nimitz during the war against Japan.

The more than 4,000 pages includes a running estimate of the situation for every day of the war in the Pacific compiled by Nimitz's planning staff, starting with Dec. 7, 1941, the day Japan attacked Pearl Harbor.

It is posted at .

War College professor John Hattendorf says it's the only such document to survive from the war.

Nimitz was commander in chief of the Pacific Fleet. He graduated from the War College in Rhode Island and lectured there several times.

The diary was declassified in 1972 but was relatively inaccessible at the Naval History and Heritage Command in Washington.