The Battle of Kwajalein was a WW2 battle of the Pacific Theater of Operation. It was fought between the US Army's 7th Inf. Div., under Charles H. Corlett, and the Japanese defense garrison, led by Akiyama Monzo, on Kwajalein, from February 1, to February 4, 1944. It was part of the Marshall Islands Campaign, which included the Battle of Eniwetok, Majuro, and Roi-Namur.
Let us remember that the Allied island-hopping campaign had begun on August 7, 1942, when the US Marines had invaded the Guadalcanal Island (Solomons). It had been followed by the US Marine Corps' capture of Tarawa (Gilberts) on November 20, 1943.
Summary
The Battle of Kwajalein began in the early morning hours of February 1, 1944, when the 184th and the 32nd Regiment, 7th Infantry Division, went ashore on Red 1 and Red 2 Beach, respectively. It had been preceded by heavy bombardment carried out by US naval guns and air raids to soften up the ground.
The Japanese troops had dug in among the torn defense building debris and uprooted trees. However, backed by field howitzers and tanks, the US troops managed to creep forward along the 800-yard wide territory of the island. To reinforce the 184th and the 32nd Regiment, additional US troops would land on Green, Blue 1 and Blue 2 Beach, on February 2.
The Japanese commander organized the resistance, mounting vicious banzai counterattacks. Nevertheless, the US advance was unrelenting as the American troops were able to mop up the last pockets of resistance on the island's Nero Point on February 4. About 90% of the 4,000 Imperial Japanese troops had been killed, while the US Army had suffered the loss of 180 men killed in action, and about 600 wounded.
Below, map of Kwajalein island, which is part of an atoll, showing the American advance in a west to east direction, and then northwards.
Mariana Islands Campaign video, with Battle of Kwajalein historical footage.