Artillery Battalion 99th Field Artillery Battalion 271st Field Artillery Battalion 1st Medical Squadron 8th Engineer Squadron 16th Quartermaster Squadron 1st Signal Troop 27th Ordnance Company 302nd Reconnaissance Troop 603rd Medium Tank Company 801st CIC Detachment Training With the attack on Pearl Harbor on 7 December 1941, the "great laboratory" phase for developing and testing organizations, about which Marshall wrote in the summer of 1941, closed, but the War Department still had not developed ideal infantry, cavalry, armored, and motorized divisions. In 1942 it again revised the divisions based on experiences gained during the great GHQ maneuvers of the previous year. As in the past, the reorganizations ranged from minor adjustments to wholesale changes. 1st Cavalry Division retained its square configuration after the 1941 maneuvers, but with modifications. The division lost its antitank troop, the brigades their weapons troops, and the regiments their machine gun and special weapons troops. These changes brought no decrease in divisional firepower, but placed most weapons within the cavalry troops. The number of .50-caliber machine guns was increased almost threefold. In the reconnaissance squadron, the motorcycle and armored car troops were eliminated, leaving the squadron with one support troop and three reconnaissance troops equipped with light tanks. These changes increased the division from 11,676 to 12,112 officers and enlisted men. The last of the 1st Cavalry Division's mounted units permanently retired their horses and converted to infantry formations on 28 February 1943. However, a mounted special ceremonial unit known as the Horse Platoon – later, the Horse Cavalry Detachment – was established within the division in January 1972. Its ongoing purpose is to represent the traditions and heritage of the American horse cavalry at military ceremonies and public events. 1st Cavalry Division reported for its port call at Camp Stoneman, CA as follows: Combat chronicle Although originally being part of the III Corps (which eventually participated in the European Theater), while training in the United States, most of the 1st Cavalry Division arrived in Australia as shown above, continued its training at Strathpine, Queensland, until 26 July, then moved to New Guinea to stage for the Admiralties campaign 22–27 February 1944. The division experienced its first combat in the Admiralty Islands, units landing at Los Negros on 29 February 1944. Momote airstrip was secured against great odds. Attacks by Japanese were thrown back, and the enemy force surrounded by the end of March. Nearby islands were