Buildup on Kwajalein

Construction in and around Kwajalein Atoll began as soon as the Americans landed. The 121st Construction Battalion landed on Roi-Namur with the 4th Marine Division, and the 109th arrived on February 9th. They quickly built the existing Japanese runway into a fighter base. The 74th and 107th Battalions reported on Kwajalein Island in March 1944, the 74th setting up headquarters on near-by Berlin, or Gugegwe Island. They used a captured Japanese coral crushing plant to build a 6,300 foot (1920 meter) airstrip that was utilized by the 11th and 30th Bomb Groups of the 7th Air Force. They attacked Eniwetok and other targets. During March 1944, the Americans took over Wotho, Ujae, and Lae Atolls in the West Marshalls; Namu, Ailinglapalap, Namorik, Ebon Atolls, and Kili Island in the south; Bikini, Rongelap, Ailinginae, and Rongerik Atolls in the north; Bikar, Utirik, Taka, Ailuk, Likiep Atolls, Jemo and Mejit Islands in the northeast; and Lib Island in a separate operation. Other bases in the Gilberts and the Marshalls were bypassed. This meant that Kwajalein became a large base of operations to keep pressure on the Japanese throughout the war. The 1st, 15th, and 52nd Defense Battalions provided security, garrison, and antiaircraft artillery. The 52nd was a segregated unit.