It is the oldest unit in the Washington Army National Guard, tracing its lineage to the separate infantry companies of the Territorial Militia.

Among them were ten companies of the 1st and 2nd Infantry Battalions of the Washington National Guard, mustered into federal service 6–13 May 1898 at Tacoma.

In what is known officially as the Philippine Insurrection and also known as the Philippine–American War, the 1st Washington participated in the Manila campaign as well as seeing additional action against the Filipino insurgents on the island of Luzon in 1899.

The First Washington—now designated the 2nd Infantry Regiment, Washington National Guard—was mustered into federal service on 28 June 1916 at Camp Elmer M. Brown, WA and was dispatched to Calexico, CA for duty.

[4] As war clouds gathered, the 2nd Infantry Regiment, Washington National Guard was called back into federal service on 25 March 1917.

It was reorganized on 1 May 1921 by consolidation with the 2nd Infantry, Washington National Guard (organized in 1918; headquarters organized 30 September 1918 and federally recognized at Spokane, Washington) and redesignation as the 161st Infantry The regiment, or elements thereof, was called up to perform the following state duties: 2nd Battalion performed duties in connection with guarding prisoners at a penitentiary in Walla Walla, 3–8 September 1926; 2nd Battalion performed strike duties in connection with an agri-labor/I.W.W.

The regiment conducted annual summer training at Camp Murray, Washington, adjacent to Fort Lewis, from 1921–39.

Initially ordered to Camp Murray on 20 September 1940, the division was transferred to Fort Lewis, Washington on 20 March 1941.

Between 5 June and 2 July 1941 the 41st participated in the IX Corps maneuvers at Hunter Liggett Military Reservation, California.

The 161st RCT was composed of the 161st Infantry, the 89th Field Artillery Battalion and other combat support units under the command of Colonel Clarence A. Orndorff.

While in reserve manning defensive positions around the airstrip, named Henderson Airfield, the 161st was also handed the assignment of eliminating a concentration of Japanese troops in what became known as the Matanikau River Pocket.

The Pocket, estimated to hold 500 enemy troops, was a dense jungle redoubt positioned between a steep hillside and a high cliff over the Matanikau River.

The heavy undergrowth masked the well-camouflaged Japanese positions, both on the ground and high in the trees, and made dislodging them a slow, grim task.

The combination, though, of frequent patrols, heavy artillery bombardment, and starvation served to eliminate this strongpoint in the end.

The 161st, back under 25th control, along with the 27th Infantry was ordered to attack north from Bibilo Hill and clear the Japanese between them and the sea.

With the battle for the Solomon Islands over, the Tropic Lightning Division returned to Guadalcanal in early November 1943 and then moved on to New Zealand.

Throughout the summer the 25th trained hard from squad level up to division, with the 35th Infantry serving as an opposing force.

In the fall the division became proficient in conducting amphibious landings in preparation for its participation in the liberation of the Philippine Islands.

Seizing the high ground northwest of the town on 22 January, the regiment found itself in a fierce fight with a determined foe.

On 25 January the 2nd Battalion resumed its advance into the town led by Cannon Company which destroyed some twenty dug-in enemy tanks and four artillery pieces and some 150 enemy soldiers while the 2nd Battalion inflicted additional heavy casualties on the retreating Japanese forces as the 161st completed the liberation of San Manuel by 28 January.

The I Corps was directed to turn north into the mountains of northern Luzon to attack the main Japanese stronghold.

The division maintained the same formation with the 161st west of the road, the 27th on the east side and the 35th leading the attack with an enveloping maneuver to take the town of Putlan.

The area was a series of rugged ridges and thick forests, making progress against a determined, well fortified enemy extremely difficult.

A heavily defended Japanese position dug into caves on Crump's Hill stopped the battalion's advance.

Plans called for the division to take part in the invasion of Japan and exercises for the assault landings were undertaken.

But with the dropping of the atomic bombs on Hiroshima and Nagasaki the war ended, and soldiers of the 25th could land on Japanese soil without taking casualties.

[4] The 161st Infantry Regiment had one Medal of Honor recipient during the war: Technician Fourth Grade Laverne Parrish The 1st Battalion, 161st along with the other elements of the 81st Armor Brigade was called to federal service in 2003 and arrived in Iraq in April 2004.

The battalion was based at Logistical Support Area Highlander adjacent to the International (Green) Zone in Baghdad.

The battalion provided security for the Green Zone and conducted full spectrum operations in southeast Baghdad.

(organized in 1898), and redesignated 9 November 1899 as 1st Infantry Regiment Redesignated in May 1903 as 2d Infantry Regiment (Companies C, K, and M withdrawn, converted, and redesignated 5th, 3d, and 2d Companies, Coast Artillery Reserve Corps; Company A disbanded, then reorganized in 1909 as 4th Company, Coast Artillery Corps) Mustered into Federal service 28 June 1916 at Camp Elmer M. Brown, Washington, for Mexican Border; mustered out 8 October 1916 at American Lake Called into Federal service 25 March 1917; drafted into Federal service 5 August 1917 Consolidated with elements of 3d Infantry Regiment, District of Columbia National Guard, and redesignated 19 September 1917 as 161st Infantry, an element of the 41st Infantry Division (United States) Demobilized 1–8 March 1919 at Camp Dix, New Jersey and Camp Dodge, Iowa State of Washington elements reorganized 1 January 1921 in the Washington National Guard as 161st Infantry; assigned to the 41st Division (1st Battalion and Supply Company withdrawn, converted, and redesignated 10 May 1921 as 146th Field Artillery Regiment (United States)) Inducted into Federal service 16 September 1940 at Spokane Relieved from assignment to the 41st Division 14 February 1942 Assigned to the 25th Infantry Division (United States) 3 August 1942 Relieved from assignment to the 25th Infantry Division and inactivated 1 November 1945 at Nagoya, Japan Assigned to the 41st Division 17 June 1946 Reorganized and Federally recognized 24 March 1947 with headquarters at Spokane Reorganized 15 April 1959 as 161st Infantry, a parent regiment under the Combat Arms Regimental System, to consist of the 1st and 2d Battle Groups, elements of the 41st Infantry Division Reorganized 1 March 1963 to consist of the 1st and 2d Battalions Reorganized 1 January 1968 to consist of the 1st, 2d, and 3d Battalions, elements of 81st Infantry Brigade Reorganized 1 May 1971 to consist of the 1st and 3d Battalions, elements of 81st Infantry Brigade, and the 2d Battalion Reorganized 1 January 1974 to consist of the 1st and 3d Battalions, elements of 81st Infantry Brigade Withdrawn 1 May 1989 from the Combat Arms Regimental System and reorganized under the United States Army Regimental System with headquarters at Spokane Reorganized 1 October 1998: Retaining the 1st Battalion as an element of the 81st Infantry Brigade, Headquarters remaining in Spokane; one company moved to Kent; Deactivating the 3rd Battalion, Headquarters and Headquarters Company (HHC) in Kent; Detachment 1, HHC (Puyallup); Company A (Kent); Company B (Kent), Company C (Redmond), Company D (Kent), and Company E (Shelton).