The 4,000-page multivolume collection includes a running summary of the situation for every day of the war in the Pacific compiled by Nimitz's planning staff. It is the only known similar document to survive from the war, said Prof. John Hattendorf, who teaches maritime history at the Naval War College in Newport, R.I.
The Nimitz "Graybook," named for the gray material in which it is bound, is posted at http://www.usnwc.edu/graybook. Traffic was so heavy Monday that downloads of the document were inaccessible for several hours. A spokeswoman for the Naval War College said the problem was mostly fixed by Monday afternoon.
The diary begins on Dec. 7, 1941, the day of the attack on Pearl Harbor, with the line: "The war opened with the attack of Japanese aircraft on Oahu." It goes on to list the locations of the Navy's forces throughout the Pacific, the damage sustained that day and what is known about the enemy's position.
Nimitz's planning staff prepared a similar summary for him every day of the war. Unlike other commanders during World War II, Nimitz kept them, and the diary was found in his personal papers, Hattendorf said.
The entries run through Aug. 31, 1945, as the war in the Pacific came to an end.
The diary was declassified in 1972 and is kept at the Naval History and Heritage Command in Washington, making it accessible only to those who can travel there. Hattendorf said the project to digitize it, make the text searchable and put it online will make it easier for scholars worldwide to study the diary and what Nimitz knew as he made command decisions.
"We'll really be able to understand in a much better way how Adm. Nimitz thought and the challenges he saw every day of the war," he said. "It can be searched for particular information, when particular information was known by the commander, how we reacted to a particular change ... what the president was telling him."
Nimitz, a native Texan who died in 1966, graduated from the War College and lectured there several times. The project was funded through the Naval War College Foundation.