The Fourth Battalion was commissioned at Camp Bradford, Virginia in May 1942 and shipped to Dutch Harbor in June 1942. The battalion was divided and served in the Aleutians on Adak, Unalaska, Amchitka, and Amaknak. Projects included building roads, submarine base, military installations, harbor docks, and living quarters for army, marine, and seabee personnel.
The battalion returned to Camp Parks, California in June 1943. After reorganizing and receiving replacements it moved to Port Hueneme, California for more training. In December 1943 the battalion was shipped to Oahu, Hawaii and built housing for nineteen Seabee battalions, a tent city for housing marines, and detached duty on Pearl Harbor docks.
The next deployment was in support of the liberation and development of Guam. A contingent of the Fourth was temporarily assigned to the Third Marines during the invasion in July 1944. The rest of the battalion waded ashore in August. The initial camp set up on Guam was destroyed by an exploding ammunition dump and there was some harassment from the Japanese that were still on the island after the island was declared secure. The major projects on Guam included a fuel drum storage dump, a naval ammunition depot, bomb storage dumps, a dam and treatment plant for water supply, a rest camp for submarine crews, and many miles of crushed coral roads. The largest project on Guam was Base 18 Hospital with 3300 beds when it was completed in time for casualties from the Battle of Iwo Jima starting on February 23, 1945, and continuing through March until 3721 patients had been received and 3534 were returned to duty.
The final deployment was in support of the planned invasion of Japan. On July 7th, the battalion and equipment was loaded on seven lst landing craft ships, joined a convoy, and sailed to Okinawa.
The battalion was on Okinawa getting ready for their duties required in the invasion of Japan, when the atomic bombs were dropped that ended the war. The battalion typically had a complement of 1087 men from the time it was commissioned until it was decommissioned on Okinawa on October 31, 1945. Over 1900 men served in its ranks.
Location. 30° 16.343′ N, 98° 52.036′ W. Marker is in Fredericksburg, Texas, in Gillespie County. Memorial is at the intersection of East Main Street and North Washington Street on East Main Street. The marker is located in the central section of the WWII Veterans Memorial Courtyard which is a part of the National Museum of the Pacific War. Marker is at or near this postal address: 340 E Main St, Fredericksburg TX 78624.