The 31st Infantry Regiment ("Polar Bears") of the United States Army was formed on 13 August 1916, and was part of USAFFE's Philippine Division during World War II. The unit is rare in that it was formed and has spent most of its life on non-American soil.
The regiment is the third to bear the designation; the first was formed for the War of 1812 and disbanded in 1815. The second was created from the 3rd Battalion of the 13th Infantry on 28 July 1866, in the reorganization of the U.S. Army following the American Civil War. The second organization to be called the 31st Infantry was consolidated with its sister regiment the 22nd Infantry (also formed out of the 13th) in an 1869 reorganization. Because the lineage of the previous regiments called the 31st were passed down to their successor units, the current 31st Infantry Regiment does not share their history or honors.
Organization
The third organization called the 31st Infantry Regiment was formed at Fort William McKinley, Philippine Islands on 13 August 1916 using cadre from the 8th, 13th, 15th, and 27th Infantry Regiments. The 1st Battalion was formed at Regan Barracks, the 2nd at Camp McGrath, and the 3rd at Fort William McKinley. It bears the distinction of being the first organization created under expansion of the US Army under the National Defense Act of 1916.
Russian Civil War
During the Russian Revolution, on 13 August 1918, the 31st moved from Manila's tropics to the bitter cold of Siberia as part of the American Expeditionary Force, Siberia. Its mission was to prevent allied war material left on Vladivostok's docks from being looted. The 31st moved from Fort William McKinley to Manila, and there set sail for Vladivostok, Siberia, arriving on 21 August. The regiment was then broken into various detachments and used to guard the Trans-Siberian railway, as well as 130 km of a branch line leading to the Suchan mines.
For the next 2 years, the 31st and its sister, the 27th Infantry Regiment, fought off bands of Red revolutionaries and White counter-revolutionaries that were plundering the Siberian countryside and trying to gain control of the Trans-Siberian Railroad. They also dissuaded their 40,000 Japanese allies from taking control of Russian territory.
The regiment suffered its first battle casualties on 29 August 1918, in action near Ugolnaya. During the Siberian deployment, 30 soldiers of the 31st Infantry were killed and some 60 troops were wounded in action. In addition, a large number of troops lost limbs due to frostbite. During this deployment, the regiment recommended one Medal of Honor and 15 Distinguished Service Crosses. For its service in Siberia, the 31st Infantry became known as "the Polar Bear regiment", adopting a silver polar bear as its insignia.
Interwar period
Part of the regiment sailed from Vladivostok on the USAT Crook in February 1920 and arrived at Manila, Philippine Islands, near the end of the month. The remainder sailed on the USAT South Bend on 30 March 1920 and arrived at Fort William McKinley, Philippines, on 16 April 1920. On 16 December 1920, the entire regiment was transferred to the Post of Manila. It was assigned to the Philippine Division on 22 October 1921, and relieved from the division on 26 June 1931.
China service
On 1 February 1932, the regiment was ordered to Shanghai, China, arriving on 4 February. There, the unit guarded a section of the International Settlement, during a period of considerable fighting between Japanese and Chinese troops. Reinforcing the 4th Marine Regiment and a predominantly British International Force, the 31st Infantry deployed hastily by sea to protect Shanghai's International Settlement. Although adjacent parts of Shanghai were demolished by fierce fighting between Japanese and Chinese troops, the International Settlement remained an island of security. By April, some officers sent for their families from Manila and billeted them at a hotel in the International Settlement. On 1 July 1932, when the crisis passed, the unit sailed for the Philippines on the USAT Republic. For their service in Shanghai, they received the Yangtze Service Medal (Marines). The regiment’s mission in the Philippine Department’s defense plan was to deploy to Corregidor and act as the beach defense force for the Harbor Defenses of Manila and Subic Bays. The regiment was reassigned to the Philippine Division in December 1941.