Built in 1931, Fort Detrick was originally used as the center of the US Army's biological weapons program. Today Fort Detrick is a part of the US Army Medical Command, and the U.S. Army Medical Research and Materiel Command (USAMRMC), and the U.S. Army Medical Research Institute of Infectious Diseases (USAMRIID) are headquartered here.

Also present at Fort Detrick are several Signal Battalions, Logistics Battalions, offices for the US Department of Health and Human Services, US Department of Agriculture, and the US Department of Homeland Security.

Established in 1861, Fort Myer was originally used as a training camp for the US Army Signal Corps, and in 1908, saw the first flight of an aircraft at a military base. During World War I was used as a staging area for engineer, chemical, and artillery soldiers. During World War II, Fort Myer was again used as a staging area for a large number of soldiers, including General Patton, who was stationed at Fort Myer for a time.

Fort Myer was joined with the US Marines Henderson Hall to make Joint Base Myer-Henderson by the 2005 Base Realignment and Closure Commission to increase the efficiency of the two military installations. Tenant units at Fort Myer include the 3rd Army (The Old Guard), which includes the sentries guarding the Tomb of the Unknown Soldier, as well as the US Army's Band "Pershing's Own", Arlington National Cemetery Honor Guard Teams, as well as numerous other units.

Fort Gordon was established in 1917, as a training base for soldiers entering World War I. The installation was reactivated shortly before World War II began, and was also enlarged - during the war Fort Gordon trained the 4th Infantry, the 26th Infantry, and the 10th Armored Divisions. Fort Gordon was used primarily as a Basic Training camp from the 1950's-1970's, as well as training for Military Police, Signal Corps Replacement Training, and the base housed the only Army Criminal Investigation Laboratory in the US.

Today Fort Gordon is still responsible for training US Army Military Police and Signals Corps personnel, as well as housing Military Intelligence and National Security Agency personnel.

Established in 1917, Fort Monmouth was used during World War I as a Signal Corps training school. During World War II, Fort Monmouth continued to be used for communications training, adding a Signal Corps Officer Candidate School.

In 2005, the Base Realignment and Closure Commission recommended Fort Monmouth close, and its units relocate to other Army installations. Fort Monmouth held its official closing ceremony in September of 2011.

Established if 1877, Fort Huachuca was originally built to counter the threat from the Chiricahua Indians and secure the Mexican-American border. From 1913-1923 Fort Huachuca housed the famous 10th Cavalry Regiment, also known as the "Buffalo Soldiers". During World War II, Fort Huachuca was used as a training area for the 92nd and 93rd Infantry Divisions, during this time the installation had an area of over 71,000 acres and housed about 25,000 soldiers.

After the Korean War, Fort Huachuca housed the US Army's Electronic Proving Ground, the US Army's Electronic Warfare Schools, US Army Communications Command, and 9th Army Signal Command. Today, Fort Huachuca still contains many of these same units, always pushing the technology in electronic and signals warfare. Other tenants at Fort Huachuca are the Fort Huachuca Museum and the US Army Intelligence Museum.