The 41st Infantry Division was an infantry division of the United States Army National Guard composed primarily of units from the Pacific Northwest. The division saw active service in World War I and World War II, receiving the nickname “Jungleers” during the latter.

Organized in 1917 after the American entry into World War I, the division was selected as a replacement division after being deployed to France as part of the American Expeditionary Forces. Its infantry units were used to provide individual replacements and the division functioned as a replacement depot. The 41st Division was reorganized in the National Guard during the interwar period, consisting of units from Oregon, Washington, Montana, Idaho and Wyoming. Sent to Australia after the Attack on Pearl Harbor, the 41st became one of the first Army units to engage in offensive ground combat operations during World War II when elements of the division were committed to the New Guinea campaign in the last months of 1942. The division suffered its heaviest casualties in the 1944 Battle of Biak at the conclusion of the campaign. In the final months of the war, the division took a major role in the liberation of the Southern Philippines, including the Palawan, Zamboanga, Eastern Mindanao and Sulu Archipelago operations. The division ended its active service in the occupation of Japan.

Postwar, the 41st Infantry Division was re-established in the National Guard, split between Oregon and Washington. The 41st Infantry Brigade was formed from mainly Oregon elements of the division in 1965 and in 1968 the division was eliminated during reductions of the National Guard. Its former units were used to form two separate brigades, the 41st Infantry Brigade in Oregon, and the 81st Infantry Brigade in Washington.

History World War I The 41st was ordered to be organized by the War Department on 18 July 1917, about three months after the American entry into World War I, from National Guard units from Idaho, Montana, Oregon, Washington state, and Wyoming. Additional units from Colorado, New Mexico, North Dakota, South Dakota, and the District of Columbia were later added to complete the division. It trained at Camp Greene, North Carolina. It consisted of the 81st Infantry Brigade (161st and 162nd Infantry Regiments) and the 82nd Infantry Brigade (163rd and 164th Infantry Regiments).McGrath, 'The Brigade,' p.170 On 26 November 1917 the 41st Division embarked for Europe as part of the American Expeditionary Force (AEF), commanded by General John J. Pershing. Men of the 41st were aboard the SS Tuscania when it was torpedoed by a German U-boat and sunk off the coast of Northern Ireland.

Order of battle Source:

Headquarters, 41st Division 81st Infantry Brigade 161st Infantry Regiment (former 2nd Washington Infantry and Companies A, B, C, and D, 3rd D.C. Infantry) 162nd Infantry Regiment (former 3rd Oregon Infantry and Companies E, F, G, and H, 3rd D.C. Infantry) 147th Machine Gun Battalion (former Machine Gun Company, 3rd D.C. Infantry, Machine Gun Troop, Washington Cavalry, Company H, 2nd North Dakota Infantry, and Machine Gun Company, 2nd Idaho Infantry) 82nd Infantry Brigade 163rd Infantry Regiment (former 2nd Montana Infantry and Companies I, K, L, and M, 3rd D.C. Infantry) 164th Infantry Regiment (former 2nd North Dakota Infantry, 1st Battalion and Machine Gun Company, 1st North Dakota Infantry, and 64 men from Headquarters Company, 3rd D.C. Infantry) 148th Machine Gun Battalion (former Companies I, K, and L, 4th South Dakota Infantry, and 2 officers from 2nd North Dakota Infantry) 66th Field Artillery Brigade 146th Field Artillery Regiment (75 mm) (former Headquarters and Supply Companies and 1st Battalion, 2nd Idaho Infantry, Battalion of Washington Field Artillery, and Battery A, New Mexico Field Artillery) 147th Field Artillery Regiment (155 mm) (former Headquarters and Supply Companies, 1st Battalion, and Companies H and M, 4th South Dakota Infantry, and Batteries A and B, Oregon Field Artillery) 148th Field Artillery Regiment (155 mm) (former Headquarters and Supply Companies and 1st Battalion, 3rd Wyoming Infantry, 1st Battalion Colorado Field Artillery, and 1st Separate Squadron Oregon Cavalry) 116th Trench Mortar Battery 146th Machine Gun Battalion (former 3rd Battalion, 2nd Idaho Infantry, Machine Gun Company, 3rd Wyoming Infantry, and Machine Gun Company, 4th South Dakota Infantry) 116th Engineer Regiment (former 2nd Battalion, 2nd Idaho Infantry, part of Headquarters Company, 2nd North Dakota Infantry, and Battalion of Oregon Engineers) 116th Field Signal Battalion (former 1st Battalion, Washington Signal Corps, and Supply Company, 3rd D.C. Infantry) Headquarters Troop, 41st Division (former Troop C, 1st Squadron Washington Cavalry) 116th Train Headquarters and Military Police (former portion of Headquarters Company, 2nd North Dakota Infantry, and Troops A, B, and D, 1st Squadron Washington Cavalry) 116th Ammunition Train (former 2nd and 3rd Battalions, 3rd Wyoming Infantry) 116th Supply Train (former Companies E, F, and G, 4th South Dakota Infantry) 116th Engineer Train (former Supply Company, 2nd North Dakota Infantry) 116th Sanitary Train 161st, 162nd, 163rd, and 164th Ambulance Companies and field Hospitals (former 1st Idaho Field Hospital, 1st Washington Field Hospital, Companies F, G, I, K, L, and M, 2nd North Dakota Infantry, detachment from 2nd Idaho Infantry, 3 officers from 3rd Wyoming Infantry, and 1 man from 4th South Dakota Infantry)

In France the 41st Division received a major disappointment when it was designated a replacement division and did not go into combat as a unit. The majority of its infantry personnel went to the 1st, 2nd, 32nd and 42nd Infantry Divisions where they served throughout the war. The 147th Field Artillery Regiment was attached mostly to the 32nd Division and saw action at the Third Battle of the Aisne, the Meuse-Argonne Offensive and other areas. The 146th and 148th Regiments of the 66th Field Artillery Brigade were also attached as corps artillery units and participated in the battles of Château-Thierry, Aisne-Marne, Saint-Mihiel and Meuse-Argonne Offensive.

Interwar period The 41st Division headquarters arrived at the port of Hoboken, New Jersey, aboard the USS Leviathan on 12 February 1919, and was demobilized on 22 February at Camp Dix, New Jersey. Pursuant to the National Defense Act of 1920, the 41st Division was reconstituted in the National Guard in 1921 and allotted to the states of Idaho, Montana, Oregon, Washington and Wyoming, and assigned to the IX Corps. The division headquarters was organized and federally recognized on 3 January 1930 at Portland, Oregon, with Major General George A. White appointed as commander; he would remain in command until his death in 1941.

The designated mobilization training center for the “Sunset” Division was Camp Murray, Washington. The division staff, composed of personnel from all five states, came together to conduct joint training for several summers before World War II, usually at Fort Lewis or Camp Murray. However, for the 1938 camp, the staff assembled for training at Fort William Henry Harrison, near Helena, Montana. The division staff also participated in the Fourth Army command post exercise at Fort Lewis in 1935 and 1936, and at the Presidio of San Francisco in 1939. From 1922 to 1939, the division’s subordinate units generally held separate summer camps at locations within their respective states: Oregon units at the state military reservation at Camp Clatsop; Washington units at Camp Murray, Montana units at Fort William Henry Harrison, and Idaho units at Boise Barracks. For the 1937 camp, the division participated in the Ninth Corps Area phase of the Fourth Army maneuvers at Centralia-Fort Lewis held in August. The 41st paired with the 3rd Division, and a "Blue Army" drawn from the 41st Division attempted a combat crossing of the Nisqually River, which was defended by a "Red Army" under the command of Brigadier General (later US Army Chief of Staff) George Marshall, then the commander of the 3rd Division's 5th Infantry Brigade at Vancouver Barracks. The 41st Division's mission was accomplished by a night crossing of the river. In 1940, the “Sunset” Division again participated in the Fourth Army maneuvers at Fort Lewis, this time as part of the provisional IX Corps.

World War II WWII division organization Square division The 41st Division's annual summer camp at Fort Lewis in June and July 1940 was extended from two weeks to three, and on 16 September 1940 with President Franklin D. Roosevelt's signing of the Selective Training and Service Act of 1940, the 41st Division was inducted into federal service for one year. It was one of four National Guard divisions to be inducted into federal service that day. The other divisions were the 30th Division, 44th Division and 45th Division. By this time, a National Guard recruiting campaign had raised the strength of the division to 14,000 – still well short of its war establishment strength of 18,500. The difference was made up by 7,000 Selective Service men, the first of whom arrived in February 1941.

At the time the division still retained its World War I square organization and consisted of the following units.

41st Division, in Portland (OR)National Guard Register for 1939, pp. 52-53 41st Division Headquarters 81st Infantry Brigade, in Tacoma (WA) Headquarters and Headquarters Company, in Camp Murray (WA) 161st Infantry Regiment, in Spokane (WA) Headquarters and Headquarters Company 3× Infantry battalions each battalion consists of: 1× Headquarters and Headquarters Detachment, 3× Rifle companies, 1× Weapons Company Anti-Tank Company (M3 37mm Anti-Tank guns) Service Company 163rd Infantry Regiment, in Whitefish (MT) same organization as 161st Infantry Regiment 82nd Infantry Brigade, in Portland (OR) Headquarters and Headquarters Company, in Portland (OR) 162nd Infantry Regiment, in Portland (OR) same organization as 161st Infantry Regiment 186th Infantry Regiment, in Medford (OR) same organization as 161st Infantry Regiment 66th Field Artillery Brigade, in Seattle (WA) Headquarters and Headquarters Battery, in Seattle (WA) 146th Field Artillery Regiment, in Seattle (WA) Headquarters and Headquarters Battery 2× Light Field Artillery battalions Headquarters and Headquarters Battery 3× Howitzer batteries (M1897 75mm field guns), replaced by M2 105mm towed howitzers in 1941) Service Battery 148th Field Artillery Regiment, in Tacoma (WA) same organization as 146th Field Artillery Regiment 218th Field Artillery Regiment, in Portland (OR) Headquarters and Headquarters Battery 2× Medium Field Artillery battalions Headquarters and Headquarters Battery 3× Howitzer batteries (M1918 155mm towed howitzers, replaced by M1 155mm towed howitzers in 1941) Anti-Tank Battery (M1897 75mm anti-tank guns) Service Battery 116th Engineer Regiment, in Boise (ID) Headquarters and Headquarters and Service Company 2× Engineer battalions each battalion consists of: 1× Headquarters, 3× Engineer companies 116th Medical Regiment, in Seattle (WA) Headquarters and Headquarters and Service Company Collecting Battalion battalion consists of: 1× Headquarters, 3× Collecting companies Ambulance Battalion battalion consists of: 1× Headquarters, 3× Ambulance companies Clearing Battalion battalion consists of: 1× Headquarters, 3× Clearing companies 116th Quartermaster Regiment, in Seattle (WA) Headquarters and Headquarters Company 2× Truck battalions each battalion consists of: 1× Headquarters, 2× Truck companies Light Maintenance and Car Battalion battalion consists of: 1× Headquarters, 1× Light Maintenance Company, 1× Car Company Service Company Headquarters, Special Troops, in Centralia (WA) Headquarters Company, 41st Division, in Blackfoot (ID) 41st Signal Company, in Portland (OR) 116th Ordnance Company, in Jerome (ID)