Liberation of Batangas proper by American forces began in March 1945 under the 11th Airborne Division and the 158th Regimental Combat Team (or 158th RCT). The 158th Regimental Combat Team stationed in Nasugbu was tasked to secure the shores and nearby towns of Balayan and Batangas. The 11th Airborne Division from the Tagaytay Ridge would attack the Japanese defenses north of Taal Lake and open the Lipa corridor. By March 11 the 158th RCT had reached Batangas City. In order to secure the two bays, 158th RCT needed to capture the entire Calumpang Peninsula near the town of Mabini, which was still held by some elements of the Japanese 2nd Surface Raiding Base Force. Fighting continued until March 16 when the whole peninsula was finally captured.