The base became operational in the fall of 1941, with the purpose of being the home to Marine Expeditionary Forces. It was named after Lt. General John Archer Lejeune, who served as a Marine in various stations for 40-plus years during the late 1800's and early 1900's and fought in the Spanish-American War and World War I.

Camp Lejeune is located along 14 miles of beach, making it idea for amphibious assault training, and is between the two deep-water ports of Wilmington and Morehead City. In addition, Lejeune is supported by 5 satellite facilities: Marine Corps Air Station New River, Camp Geiger, Stone Bay, Courthouse Bay, Camp Johnson, and Greater Sandy Run Training Area.

Some of Camp Lejeune's core tenants are Marine Corps Base Camp Lejeune, II Marine Expeditionary Force, 2nd Marine Division, 2nd Marine Logistics Group, and the naval hospital.

The II Marine Expeditionary Force, one of Lejeune's core tenants, is an Air-Ground Task force with ground/air/logistics assault capabilities that is capable of maintaining itself in the field without any outside assistance for a period of up to 60 days. It is made up of the 2nd Intelligence Battalion, 2nd Radio Battalion, 2nd Law Enforcement Battalion, 8th Communication Battalion, and 2nd ANGLICO (Air Naval Gunfire Liaison Company), and has seen combat in three engagements: Operation Desert Storm of the Persian Gulf War; Operation Enduring Freedom of the Global War on Freedom; and Operation Iraqi Freedom of the Iraq War.

The 2nd Marine Division is the ground combat element of the II Marine Expeditionary Force and has been in existence since the February 1st 1941, and has seen combat in the three aforementioned engagements; however, the 6th Marine regiment, which is part of the Division can trace its combat history back as far as WWI.

Another major tenant, the 2nd Marine Logistics Group, has worn many hats and seen numerous locations since its inception in 1944 at Pearl Harbor Fleet Marine Force's 8th Field Depot for Supply Service. Its most notable venues of wartime theater include the Battle of Iwo Jima, the Cuban Missile Crisis, and of course the Iraq War, with relief work following Hurricane Andrew in Miami-Dade County, and Operation Provide promise in Bosnia Herzegovina.