War Plan Orange
On December 24, MacArthur invoked the prewar plan WPO-3 (War Plan Orange 3), which called for use of five delaying positions in central Luzon while forces withdrew into Bataan. This was carried out in part by the 26th Cavalry Regiment. He relieved General Parker of his command of South Luzon Force and had him begin preparing defensive positions on Bataan, using units as they arrived; both the military headquarters and the Philippine's government were moved there. Nine days of feverish movement of supplies into Bataan, primarily by barge from Manila, began in an attempt to feed an anticipated force of 43,000 troops for six months. (Ultimately 80,000 troops and 26,000 refugees flooded Bataan.) Nevertheless, substantial forces remained in other areas for several months.