At the beginning of the Korean War was the battle of the Chosin Reservoir, where the Chinese attempted to push the United Nations out of Korea from November to December 1950.
Getting To North Korea
The X Corps landed at Inch'on in September 1950. They were sent by President Harry S. Truman and the UN General Assembly to go after the Korean People's Army.
On October 7, the U.S. Eighth Army headed toward Korea's capital of P'yongyang on General Douglas MacArthur's order, while the X Corps went east. Unbeknownst to MacArthur, the Chinese were concerned about an attack from the area and sent troops and supplies.
The Chinese had 33 divisions in North Korea ready to attack the UNC forces. In October, Mao Zedong ordered the divisions to attack the Eighth Army. The Chinese First Offensive hit the Eighth Army hard in the battle of Onjong-Unsan. The Marines and South Korean I Corps won the battle, killing 662 Chinese soldiers.
MacArthur did not realize how many soldiers the CPVF had when he told Almond to move inland toward the Chosin Reservoir. Soldiers moved forward through a small unpaved road covered in snow, with blinding snowstorms and freezing weather.
The X Corps was moving toward Hagaru-ri, which was at the southern edge of the reservoir. Their supplies were coming in via truck, and the 1st Marine Division set up bases in villages along their route in Chinhung-ri and Kot'o-ri.
General Smith thought the mission was too risky and convinced Almond to keep the majority of the Marines in Hagaru-ri, and 3,200 Americans and Korean went to the east of Chosen with Task Force MacLean.
The Chinese Ninth Army Group had 150,000 soldiers and was ordered to attack the 1st Marine Division. The Ninth Army surrounded X Corps and the 1st Marine Division with its five divisions and attacked simultaneously.
After three days of relentless nighttime attacks, most Marines held their positions, except Task Force MacLean, who was scattered. When they came back together, there were about 670 soldiers, but only half could fight.
Overall, the battle was a victory for the Chinese, and the X Corps eventually became a part of the Eighth Army. However, the estimated losses for the Chinese are between 40,000- 80,000, while the 1st Marine Division lost just under 12,000.