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. 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). On 26 November 1917 the 41st Division embarked for Europe as part of the American Expeditionary Force (AEF), commanded by General