Initially Lieutenant Colonel Donald Van Bonnett was appointed to start organizing its troops.

26th Cavalry was to cover the right flank of 71st Division and hold the junction of Rosario-Baguio road, east of Rosario in order to permit the 71st Infantry Regiment (less 1st Bn) under LCol.

Donal Van Bonnett then at Baguio to clear that point and join North Luzon Force.

On January 6, 1942, the 71st Infantry Division under Brigadier General Selleck was posted at Layac Junction in Dinalupihan, Bataan supported by the 31st US Infantry Regiment under Colonel Charles Steele, 26th US Cavalry (Motorized) Regiment of Colonel Clinton Pierce with supporting units of artilleries, Light tanks, and self-propelled guns fought Imai detachment of 48th IJA Division.

The junction was a key position based on WPO 3 and designated as a first line of resistance (MLR) of the combined Fil-American forces.

In this battle, Sergeant Jose Calugas (MOH) eluded bullets to take over a fallen comrade's machine gun and led a group of volunteers, and engaged the Japanese in a shootout thus enabling other soldiers to take advantageous positions to defend the line.

Julian Chua and Cecilio Garcia were also awarded Distinguished Service Cross for exhibiting exceptional courage.

[4] The division saw action in defending Quinauan Point from the Japanese landings in the western coast of the Bataan peninsula.

Gabriel Gador commander of 7th Military District requested to call to arms all reserve soldiers and activated 74th Provisional Infantry Regiment under the command of Major Sam Jones to defend Negros Occidental and later 75th Provisional Infantry Regiment under LCol.

Colonel Roger Hilsman arrived to take matters on Negros defense and became a component of Visayan Force of BGen.