Question: Where was the  decisive battle which John U. D. Page received the Medal of Honor for his actions in held in
Context: The Battle of San Juan Hill (1 July 1898), also known as the battle for the San Juan Heights, was a decisive battle of the Spanish–American War.  The San Juan heights was a north-south running elevation about 2 km east of Santiago de Cuba, Cuba.  The names San Juan Hill and Kettle Hill were given to the location by the Americans.  This fight for the heights was the bloodiest and most famous battle of the war.  It was also the location of the greatest victory for the Rough Riders, as claimed by the press and its new commander, Theodore Roosevelt, who was to eventually become first vice-president and then president, and who was posthumously awarded the Medal of Honor in 2001 for his actions in Cuba.  The American press at the time overlooked the fact that the Buffalo Soldiers of the 10th Cavalry and 24th Infantry Regiments had actually done much of the heaviest fighting. The Battle of Chosin Reservoir, also known as the Chosin Reservoir Campaign or the Changjin Lake Campaign (Korean: 장진호 전투 ; hanja: 長津湖戰鬪; rr: "Jangjin ho jeontu"; ), was a decisive battle in the Korean War.  The name "Chosin" is derived from the Japanese pronunciation ""Chōshin"", instead of Korean pronunciation John Upshur Dennis Page (February 8, 1904 – December 11, 1950) was a United States Army officer from Saint Paul, Minnesota.  Lieutenant Colonel Page received the Medal of Honor for his actions in the Battle of Chosin Reservoir during the Korean War. The Battle of Teruel was fought in and around the city of Teruel during the Spanish Civil War.  The combatants fought the battle between December 1937 and February 1938, during the worst Spanish winter in twenty years.  The battle was one of the bloodier actions of the war with the city changing hands several times, first falling to the Republicans and eventually being re-taken by the Nationalists.  In the course of the fighting, Teruel was subjected to heavy artillery and aerial bombardment.  The two sides suffered over 140,000 casualties between them in the two-month battle.  It was a decisive battle of the war, as Francisco Franco's use of his superiority in men and material in regaining Teruel made it the military turning point of the war. The Battle of Chipyong-ni (French: "Bataille de Chipyong-ni" ), also known as the Battle of Dipingli (), was a decisive battle of the Korean War, that took place from 13–15 February 1951 between American and French units of the US 23rd Infantry Regiment and various units of the Chinese People's Volunteer Army (PVA) around the village of Chipyong-ni, present-day Jipyeong-ri.  The result was a United Nations Command victory.  The battle, along with the Third Battle of Wonju, has been called "the Gettysburg of the Korean War," and represents the "high-water mark" of the Chinese incursion into Korea.  Due to the ferocity of the Chinese attack and the heroism of the defenders, the battle has also been called, "...one of the greatest regimental defense actions in military history." The Battle of Dyrrachium (or Dyrrhachium) on 10 July 48 BC was a battle of Caesar's Civil War in the area of the city of Dyrrachium (in what is now Albania).  It was fought between Julius Caesar and the army led by Gnaeus Pompey with the backing of the majority of the Roman Senate.  The battle was a victory for Pompey, albeit not a decisive one.  The battle preceded the Battle of Pharsalus which was the decisive battle of the Civil War. The Battle of Yehuling, literally the Battle of Wild Fox Ridge, was a major decisive battle fought between the Mongol Empire and Jurchen-led Jin dynasty during the first stage of the Mongol conquest of the Jin dynasty.  The battle was fought between August and October 1211 at Yehuling (野狐嶺; lit.  "Wild Fox Ridge"), which is located northwest of present-day Wanquan District, Zhangjiakou, Hebei Province.  The battle, which concluded with a decisive Mongol victory, was followed by the assassination of the Jin emperor, Wanyan Yongji, by one of his generals and Mongol control of the central plains.  It also hastened the weakening and decline of the Jin dynasty.  Though the Jin were far more powerful at the onset of the campaign, after Yehuling the Mongols firmly held the initiative. The Decisive Battle Doctrine (艦隊決戦 , Kantai Kessen; "naval fleet decisive battle" ) was a naval strategy adopted by the Imperial Japanese Navy following the Russo-Japanese War.  It called on the use of a strong battleship force, which would at a single stroke destroy an invading fleet as it approached Japan after suffering losses through attrition as it penetrated Japanese perimeter defenses. The Battle of Ganjgal was a battle in the War in Afghanistan fought between American and Afghan forces and the Taliban in Kunar Province, Afghanistan on September 8, 2009.  Complaints that the coalition casualties were avoidable and caused by a failure of the chain of command to provide fire support for the team triggered an official investigation and a series of reprimands to several US military officers.  Army Captain William D. Swenson and Marine Corporal Dakota Meyer received the Medal of Honor for their actions during the battle.  Meyer is the first living Marine to receive the Medal of Honor since the Vietnam War, and Swenson is the fifth living Soldier and first officer to receive the Medal of Honor since the Vietnam War.  Two other Marines at the battle, Staff Sgt. Juan Rodriguez-Chavez and Capt. Ademola Fabayo, received the Navy Cross. The term decisive victory refers to a military victory in battle that definitively resolves the objective being fought over, ending one stage of the conflict and beginning another stage.  Until a decisive victory is achieved, conflict over the competing objectives will continue.  Like all concepts of warfare, a decisive battle can take place from the tactical or unit level (Pavlov's House during the Battle of Stalingrad or the Chew House at the Battle of Germantown), the operational level (the Battle of Cowpens or the Battle of Cannae), all the way up to the strategic level (the Battle of Saratoga) or battles that bring an end to hostilities, such as the Battle of Hastings, or the Battle of Waterloo.
Answer: the Korean War.