Fall back to the Final Defense Line January 27 – 29
Eisenhower and Wainwright decide after the heavy losses suffered at 1st Bataan that it is time to fall back to the prepared Final Defense Line, which the engineers of the USAFE have been preparing since November 1941. With the Japanese reeling and still falling back to reorganize, now is the perfect opportunity. Once again the cavalry troopers of the 26th and 112th Cavalry take up positions as the rear guard, supported by the 101st Infantry Brigade, all veterans of the phased retreat to Bataan. The rest of the USAFE is pulled back to the Bagac-Pilar Line over the course of the next two days.
Needing fresh troops, and running low on American infantry for the 31st and 65th Infantry regiment, Eisenhower orders the 91st Infantry Brigade (with its two regiments, the 91st and 92nd PA Infantry) which have been training at Corregidor since November 1941 broken up as replacements, while the 16th Naval District moves both of the American regiments (down to 40% strength) to Corregidor to replace them. Both American regiments are reorganized as single battalions, and excess personnel are either assigned to the 6th Cavalry or assigned to special group that Eisenhower intends to evacuate from the Philippines. Also sent over is the 1st Engineer Regiment (Philippine Army) which together with the 2 American battalions provides Corregidor with an infantry defense force of 3,500 US and Filipino troops. This also reduces the total garrison of Corregidor to 14,000 men (and 67 Filipino and American women nurses).
The engineers are again culled for manpower to serve as infantry replacements as well, which along with the disbanded 91st Brigade provides 12,000 replacements in all which is enough to make good all Filipino losses to date. As losses to date number 10,000, including those lost to attrition (and only about 3,000 are likely to return), this infusion of manpower is more than welcome and indeed allows combat units to send a large number of the more shaken and emotionally exhausted men to the rear for duties in service and combat support units. The Cavalry pulls back on January 30, and again goes into reserve. Homma meanwhile cautiously probes forward but as his combat units are badly mauled, he is unwilling to push just yet. He is unsurprised to find yet another American fortified line waiting for him 15-20 kilometers behind the initial American line.
Luzon Force (General Ord on February 1, 1942)
Bataan Force (Wainwright) (103,000 men)
I Corps (King) (42,000 men)
1st Philippine Infantry Division (1st PA, 2nd PA, 3rd PA)(11,000 men)
51st Philippine Infantry Division (51st PA, 52nd PA, 45th PS) (11,000 men)
12th Infantry Division (57th PS, 13th PA, 92nd PA,) (11,000 men)
Corps HQ and artillery (9,000 men)
II Corps (Parker) (42,000 men)
21st Infantry Division (21st PA, 25th PA, 26th PA) (11,000 men)
11th Infantry Division (11th PA, 12th PA, 43rd PS) (11,000 men)
23rd Infantry Division (47th PS, 53rd PA, 91st PA) (11,000 men)
Corps HQ and artillery 9,000 men)
Reserve (Lim) (19,000 men)
101st Infantry (PA) (attached 192nd Tank Battalion (US), 3rd Coast Artillery (mobile AA)(PA) (3,000 men)
6th Cavalry Brigade w 26th Cavalry (PS), 112th Cavalry (US NG), 194th Tank Battalion, (1,500 men)
Bataan Engineer Group (PA)(3,000 men)
USMC 1st Separate Battalion
4th Coast Artillery (PA)(AA)(2,000 men)
Bataan HQ, support and artillery reserve (9,500 men)
Manila Bay Defenses (General Moore)
Fort Mills (Corregidor), Fort Drum, Fort Hughes, Fort Frank (14,000 men) includes coast defense troops and the infantry garrison of 31st US, 65th US, and 1st Engineer Brigade (PA)
US Army Visayen Force (Ord)
General Ord is sent by air to take command of all US Army forces outside of Bataan, including stay behind forces that are now being created and placed into position through out the islands, including from behind Japanese lines in Luzon, by boat and light transport aircraft. The least effective men of the IV Corps are left to man the IV Corps, 31st and 41st Infantry Divisions (which now fall to a strength of 2,500 men each) with muster roles altered to reflect those units suffering heavy attrition from disease and desertion. This allows Ord to send 20,000 men into the hills throughout the islands with orders to lay low until contact is restored with USAFE in Australia at a future date. The remaining 4,000 men at Cebu and Mindanao are prepared for evacuation by ship and aircraft. Eisenhower wants to evacuate them to act as cadre as a future Philippine Scouts for when the Philippines are liberated in the future.
Meanwhile Homma is forced to ask the Imperial General Staff for 30,000 replacements, not only for those lost at 1st Bataan but the significant losses suffered from the landing to present.