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 counterrevolutionaries 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 men of the 31st Infantry were killed, and some 60 men 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.

World War II On 8 December 1941, Japanese planes attacked U.S. military installations in the Philippines. A 31st Infantry sergeant on detail at Camp John Hay in Baguio became the campaign's first fatality. After landing in northern and Southern Luzon, the Japanese pushed rapidly toward Manila, routing hastily formed Philippine Army units that had little training and few heavy weapons. The 31st Infantry covered the withdrawal of American and Philippine forces to the Bataan Peninsula. Unfortunately, the peninsula had not been provisioned with food and medicine and no help could come in from the outside after much of the Pacific fleet was destroyed at Pearl Harbor and mid-ocean bases at Guam and Wake Island were lost. Despite starvation, disease, no supplies, obsolete weapons, and often inoperative ammunition, the peninsula's defenders fought the Japanese to a standstill for 4 months, upsetting Japan's timetable for Asia's conquest. When Major General King announced he would surrender the Bataan Defense Force on 9 April 1942, the 31st Infantry buried its colors and the cherished Shanghai Bowl to keep them out of enemy hands. Some of the 31st's survivors escaped to continue resisting, but most underwent brutal torture and humiliation on the Bataan Death March and nearly three years of captivity. Twenty-nine of the regiment's men earned the Distinguished Service Cross and one was recommended for the Medal of Honor, but the entire chain of command died in captivity before the medal recommendation could be formally submitted. Roughly half of the 1600 men of the 31st Infantry who surrendered at Bataan perished while prisoners of the Japanese.

Perhaps of note, the Shanghai Bowl was later recovered due to the efforts of Cpt. Earl R. Short (who had buried it) after his release from a POW camp, and Col. Niederpreum. He returned to Corregidor Island under the orders of Major General Marshall in September 1945 to retrieve the bowl from its hidden location. While he was able to pinpoint the area, others had to continue the excavation until it was located in December 1945. The Bowl and Cups were found a yard and a half from where Cpt. Short had remembered them to be. And so, the trophy and symbol of the 31st Regiment was returned to them.

Korean War

In January 1946, General MacArthur restored his former guard of honor to active service at Seoul, Korea, assigning the 31st to the 7th Infantry Division. For the next 2 years the 31st Infantry performed occupation duty in central Korea, facing the Soviet Army across the 38th Parallel. In 1948, the occupation of Korea ended and the regiment moved to the Japanese island of Hokkaido, occupying the land of its former tormentor. When North Korean troops invaded South Korea in the summer of 1950, the 31st Infantry was stripped to cadre strength to reinforce other units being sent to Korea. In September, the regiment was restored to full strength with replacements from the U.S. and Koreans (KATUSA) hastily drafted by their government and shipped to Japan for a few weeks training before returning to their homeland as members of American units. The 31st Infantry returned to Korea as part of MacArthur's Inchon invasion force.

In November 1950, the 31st Infantry made its second amphibious invasion of the campaign, landing at Riwŏn, not far from Vladivostok where the 31st had fought just 30 years before. With North Korean resistance shattered, UN troops pushed toward the Yalu River. When Chinese troops swept down from Manchuria, they surrounded a task force led by the 31st Infantry's commander, COL Allan MacLean. COL MacLean and his successor, LTC Don C. Faith, were both killed during the ensuing battle. LTC Faith was awarded the Medal of Honor posthumously for his gallant attempt to lead the command to safety.

COL William J. McCaffrey assumed command of the 31st Infantry as they fought against desperate odds on the east side of the Chosin Reservoir from the night of 27 November until 1 December while the Marines did likewise on the west side. Several hundred 31st Infantry survivors managed to make it across the frozen reservoir to the Marines' lines the night of 1 December and the next day, and accompanied the Marines in their fighting withdrawal from the Chosin to Hungnam from 1–11 December 1950. Of the task force's original complement of nearly 3300 men, only 385 of those who reached Marine lines at Hagaru-ri from the inlet were unwounded. Not one vehicle or piece of heavy equipment made it through. An example of courage shown by unit members is the DSC awarded to Sergeant George H. Paine:

Citation: The Distinguished Service Cross is awarded to Sergeant George H. Paine, United States Army, for extraordinary heroism in action while serving with Company H, 31st Infantry Regiment, Seventh Infantry Division, on 30 November 1950, near Koto-ri, Korea. He was with the leading element of the Second Battalion moving north to link up with friendly units when the column was attacked by enemy who were entrenched and concentrated on high ground along the route of advance. Sergeant Paine located several enemy positions on a hillside from which automatic-weapons and small-arms were firing. Bravely and without regard for his own personal safety, he advanced alone against these positions, exposing himself to draw their fire from other elements of the column who were regrouping to make an attack. In his advance, he neutralized two enemy automatic weapons, permitting friendly troops to advance without casualties. Joining the attacking troops of the battalion, he assisted in driving the enemy from their positions around the hilltop. During this action Sergeant Paine was mortally wounded while fiercely resisting enemy forces counterattacking in an attempt to retain the hilltop. This counterattack was repulsed with heavy loss of enemy personnel. The courageous actions of Sergeant Paine were an inspiration to his comrades and enabled the battalion to complete its mission. - HQ Eighth US Army Korea, General Orders No. 113 (4 March 1951).

The remnants of the regiment was evacuated from North Korea by sea to Pusan. There it rebuilt, retrained, and refitted and was soon back in combat, stopping the Chinese at Chechon, South Korea and participating in the counteroffensive to retake central Korea. Near the Hwacheon Reservoir, two men of the regiment earned the Medal of Honor in some of the war's most determined offensive combat. By the summer of 1951, the line stabilized near the war's start point along the 38th Parallel.

31st Infantry's 1st Battalion has the distinction of being the first Army battalion to be commanded by an ethnic minority on the battlefield, when COL McCaffrey promoted then MAJ Young-Oak Kim upon his return in August 1951 from injuries sustained during a friendly fire incident when his unit became the first American troops to cross beyond the 38th parallel and thought to be too far north to be friendly during Operation Piledriver.

For the next two years, a seemingly endless series of blows were exchanged across central Korea's cold, desolate hills. Names like Old Baldy, Pork Chop Hill, Triangle Hill, and OP Dale are among the war's most famous battles, all fought by the 31st Infantry and bought with its blood. By the war's end, the 31st Infantry had suffered many times its strength in losses and 5 of its men had earned the Medal of Honor, Ralph E. Pomeroy (20 May 1951), Benjamin F. Wilson (5 June 1951), Jack G. Hanson (7 June 1951), and Edward R. Schowalter Jr. (14 October 1952) .