That would be Admiral Chester Nimitz.
U.S. Pacific Fleet
Admiral Isoroku Yamamoto, Commander of the Japanese Combined Fleet, was in overall control of planning for the 1941 surprise attack on the United States Pacific Fleet at Pearl Harbor. Vice Admiral Chuichi Nagumo was commander specifically of the Pearl Harbor Striking Force.
Overall Allied command in the Pacific Theater of Operations (PTO) was two-fold: General Douglas MacArthur commanded the South West Pacific region, which encompassed Australia, New Guinea, and the Philippines, among other islands. Admiral Chester Nimitz commanded the Pacific Ocean region, which encompassed all Pacific areas north of MacArthur's command-area.
The first big US victory in the Pacific and a decimating blow to the Japanese Navy which cruched their carrier fleet.
Dewey commanded a U.S. fleet that destroyed the Spanish fleet in the Philippines.
U.S. Navy Commander in Chief, Pacific Fleet (CINCPAC) Admiral Chester W. Nimitz (a native of Fredericksburg, Texas) commanded the Pacific Fleet in the PTO during WWII.
United States Pacific Fleet was created in 1907.
The Allies divided the world into Theaters of Operations, of which there were two in the Pacific, the Central Pacific Theater and the Southwest Pacific Theater. There was also a China-Burma-India Theater. US Army General Douglas MacArthur was commander of the Southwest Pacific Theater. US Navy Admiral Chester Nimitz commanded the Central Pacific, and he was also commander of the US Pacific Fleet. Nimitz usually had the six divisions of US Marines, and Army troops as well under his command, plus US Army Air Force units. British General Lord Louis Mountbatten commanded the China-Burma-India Theater.
by the US navy and Pacific Fleet
There were two. Admiral Chester Nimitz, based in Hawaii, commanded the Central Pacific, and also the US Pacific Fleet. Army General Douglas MacArthur, initially based in Australia after escaping from the Philippines, commanded the Southwest Pacific . There was also a China-Burma-India Theater of Operations in the war against Japan.
The US Fleet was not told of such an attack.
The Pacific was divided into two "Theaters" of Operations - the Central Pacific, and the Southwest Pacific. This was done mostly because MacArthur had retreated to Australia after Japan conquered the Philippines, and as a former commanding general of the US Army, a prestigious command had to be carved out for him. So, MacArthur commanded in the Southwest Pacific, fighting in the New Guinea area and the Philippines. Navy Admiral Chester Nimitz commanded in the Central Pacific, from his HQ in Hawaii, where he was also commander of the US Pacific Fleet.
1853
Japanese
He commanded the US Asiatic Fleet.
to open the ports of japan to commerce
Fleet Admiral Chester Nimitz. He was the Commander-in-Chief of Pacific Fleet. General Douglas MacArthur led the Army in the Pacific.