The Army has served in Alaska since 1867, when Soldiers of the United States Army, 9th Infantry Regiment, took part in the ceremonies that raised the Stars and Stripes over Sitka and transferred Russian lands to the United States. Construction of an Army post six miles northeast of Anchorage began on 8 June 1940. The War Department General Order Number 9, dated 12 December 1940, designated the military reservation as Fort Richardson, and the flying field at Fort Richardson was designated Elmendorf Field.

Following the Japanese attack on Pearl Harbor in 1941, Army and Navy engineers began building airstrips in the Aleutian Islands to defend against possible Japanese attacks. U.S. Army units also built an initial pioneer road in 1942 for the Alaska-Canada (ALCAN) Highway in less than eight months. In 1943, civilian contractors followed and constructed a more permanent, all-weather highway. The 1,420-mile road was built as an overland supply route to get personnel and equipment to Alaska. The ALCAN Highway complimented military infrastructure that was built throughout Alaska than ensured Allied forces could defend the territory, and carry the fight to the enemy, if necessary.

After the Japanese seizure of Attu and Kiska islands in the Aleutian Chain in June, 1942, the U.S. prepared 11,000 troops to retake Attu Island in May of 1943. The successful battle by the U.S. to retake Attu Island was proportionately one of the most costly amphibious assaults of World War II in the Pacific in terms of American casualties suffered. The Japanese secretly evacuated Kiska in late-July, 1943, several weeks prior to U.S. and Canadian forces seizing the island in mid-August, 1943. At the end of the war, most Army installations throughout the state closed permanently or transferred to other agencies.

The Alaskan Command (ALCOM) was created in January, 1947. As the first Unified Command under the Department of Defense, ALCOM was headquartered at Elmendorf Air Force Base near Anchorage where it controlled all military forces in Alaska.

When the Air Force was organized from the Army Air Corps in 1947, steps were taken to convert Fort Richardson and Elmendorf Field into separate installations. On 15 October 1950, the Army released the land to the Air Force that is now Elmendorf Air Force Base and began construction of new facilities at its present Fort Richardson site, eight miles from Anchorage. USARAL headquarters moved to its new location on 3 January 1953. During and shortly after the war years, several posts were established in Alaska. Some were inactivated and several became Air Force bases. The Army installation known as Fort Greely (near Big Delta, Alaska) was initially occupied by Army Forces in 1941 and became the site for Army cold weather maneuvers. The forerunner of today’s United States Army Cold Region Test Center (CRTC) and the United States Army Northern Warfare Training Center (NWTC). This location became an established Army post called “Big Delta, Alaska” on 6 May 1947. On 21 June 1953, the name was changed to “Fort Greely, Alaska.” On 1 January 1961, Ladd Air Force Base (near Fairbanks) was transferred to Army jurisdiction and was named “Fort Jonathan M. Wainwright.”

USARAL was discontinued as a major subordinate command on December 31, 1972, and the 172nd Infantry Brigade (Alaska), headquartered at Fort Richardson, assumed command and control, reporting to U.S. Army Forces Command at Fort McPherson, Georgia. The 171st Infantry Brigade was inactivated in 1973 leaving the reorganized 172nd Infantry Brigade (Separate) as the principal combat formation, split-stationed at both Fort Richardson and Fort Wainwright.

The 6th Infantry Division (Light), headquartered at Fort Richardson, was activated in 1986, replacing 172nd Infantry Brigade (Separate). The 6th ID (L) Division headquarters moved to Fort Wainwright in 1990. The 6th 1D (L) maintained an Arctic focus in its unit training and was actively involved in training exercises in Japan and Thailand, at the Joint Readiness Training Center in Arkansas and Louisiana, and throughout Alaska until its inactivation in July 1994. At that time, Army forces in Alaska reorganized under the command of U.S. Army Alaska (USARAK), headquartered at Fort Richardson, with the 172nd Infantry Brigade as the principal combat formation, split-stationed at both Fort Richardson and Fort Wainwright.

The Army underwent a major transformation in the early 2000's that witnessed a significant expansion of forces in Alaska, to include activation of two Brigade Combat Teams and numerous supporting organizations. The Army worked closely with the U.S. Air Force to incorporate Fort Richardson into a Joint Base in 2010, expanded infrastructure at Fort Wainwright, and improved ranges operated within the Joint Pacific-Alaska Range Complex, especially in central Alaska in and around Eielson Air Force Base and Fort Greely.

Today, USARAK is headquartered at Joint Base Elmendorf-Richardson and Fort Wainwright, aligned as a major subordinate command of U.S. Army Pacific (USARPAC). USARAK provides trained and ready forces in support of worldwide unified land operations; supports theater engagement in the Pacific/Arctic and military operations in the Alaska Joint Operations Area, in order to contribute to a stable and secure operational environment. The 1st Stryker Brigade Combat Team, 25th Infantry Division is headquartered at Fort Wainwright, near Fairbanks, along with Northern Warfare Training Center (NWTC) and U.S. Army Garrison Alaska. 4th Brigade Combat Team (Airborne), 25th Infantry Division, SFC Christopher R. Brevard Noncommissioned Officer's Academy, and selected units of the 17th Combat Support Sustainment Battalion are stationed at Joint Base Elmendorf-Richardson.