When did General MacArthur take over the pacific forces?

MacArthur had "retired" after four years as Chief of Staff of the US Army in 1935 and taken a position as Field Marshal of the Philippine Army. The Philippines were still a US possession. MacArthur was recalled to active duty in July 1941 and named Commander United States Forces Far East (USFFE). After MacArthur escaped from the Philippines and reached Australia he was named Supreme Commander Southwest Pacific Area (SWPA) in May 1942. Admiral Nimitz commanded the Central Pacific, and the SWPA was a theater carved out for MacArthur, in deference to his seniority. It would not have been done for anyone else.