The Battle of Kwajalein was fought as part of the Pacific campaign of World War II. It took place 31 January – 3 February 1944, on Kwajalein Atoll in the Marshall Islands. Employing the hard-learned lessons of the Battle of Tarawa, the United States launched a successful twin assault on the main islands of Kwajalein in the south and Roi-Namur in the north. The Japanese defenders put up stiff resistance, although outnumbered and under-prepared. The determined defense of Roi-Namur left only 51 survivors of an original garrison of 3,500.

The V Amphibious Corps (VAC) was a formation of the United States Marine Corps which was composed of the 3rd, 4th and 5th Marine Divisions in World War II. The three divisions were the amphibious landing force for the United States Fifth Fleet with two goals, removal of Japanese forces from islands so U.S. Seabees could build advance bases to project US power. In doing this VAC was notably involved in the battles for Tarawa, Saipan, and Iwo Jima. V Amphibious Corps was commanded by General Holland 'Howlin Mad' Smith followed by General Harry Schmidt.