U.N. forces were moving through North Korea, having pushed the NKA back across the 38th Parallel. The 1st Marine and 7th Infantry divisions, comprising X Corps, were moving toward the village of Hagaru-ri, rested near the southern tip of the Chosin reservoir. The Chinese entered the war with ground forces supported by Soviet air forces and multiple divisions engaged the 1st Marines. What became a major battle saw the outnumbered Marines hold off the Chinese 9th Army Group and then make a fighting withdrawal with the battle of the Chosin Reservoir becoming one of the most storied exploits in Marines Corps lore.