Christopher Donner - Pacific Time on Target: Memoirs of a Marine Artillery Officer, 1943-1945

Jack H. McCall Jr.

In the U.S. Army and Marine Corps, the smallest self-contained combat unit is the company (approximately 150 to 200 men, depending on the precise branch of service and tables of organization), which is known in artillery units as a battery (and in cavalry and armored units as a troop) and which is typically commanded by a captain. Companies and batteries are further divided into platoons (approximately 50 men), which are led by lieutenants, and platoons are then divided into squads (8 to 10 men; in the case of Marine rifle squads, 13 men). The next unit above the company/battery is the battalion of several hundred or more men, usually commanded by a lieutenant colonel and comprising multiple companies. As integral parts of a battalion, batteries and companies are typically identified by alphabetic designations (A Battery, E Company, etc.). The Ninth Defense Battalion, for instance, had nine line batteries, A through I, plusfor the headquarters element of each of its three groups (Seacoast, 90 mm, and Special Weapons) and for the battalions headquartersHeadquarters and Service (H&S) batteries. With more than one thousand men assigned or attached, the Ninth was an exceptionally large marine battalion. The Third Battalion of the Eleventh Marines had three line batteries plus one H&S battery.

The parent unit above the battalion level during the Second World War was typically the regiment, often commanded by a colonel. Unlike Army regiments, which specified the principal branch of service of the troops comprising it along with the regimental number (e.g., 223d Infantry Regiment, Sixth Field Artillery Regiment, 505th Parachute Infantry Regiment, etc.), Marine regiments were simply given a number, regardless of whether it was infantry or artillery, and the term regiment was not typically included when speaking of the particular regiment. Hence these regiments are called First Marines (an infantry regiment), Seventh Marines (also infantry), Eleventh Marines (field artillery), and so on. This historical quirk of marine unit designations may have partly originated from the long-standing creed of the Marine Corps that every marine is first and foremost a rifleman, and only then a specialist or branch-trained expert. With the growth of increasingly technical needs before and during World War II, however, more specialist marine units with branch-specific designations (such as the Defense and Antiaircraft battalions, Raider and Parachute regiments, and aviation units) eventually began to proliferate.

Regiments and battalions could be assembled into brigades (also often commanded by a colonel) or, more typically for both the Army and Marine Corps of this time frame, into divisions. The division was routinely commanded by a major or lieutenant general, who relied on the service of one or two brigadier generals as assistant division commanders. Divisions were further task-organized for specific campaigns or operations into corps (the highest unit of field organization in the wartime Marine Corps; for instance, I Marine Amphibious Corps or III Amphibious Corps) led by major or lieutenant generals, and then corps into armies of two or more corps, usually under the leadership of a lieutenant general or general. There were a host of other higher headquarters in the PacificCOMSOPAC (Commander, South Pacific Area) and CINCPAC (Commander in Chief, Pacific Ocean Areas) among othersbut these were typically far removed from the worms-eye view of Chris Donner and his peers and will seldom be encountered in this book.