Description MacArthur planned an amphibious landing at Inch' on, a port of the Yellow Sea 25 miles west of Seoul, to be followed by an advance to recapture the city and block North Korean troop movements and supply routes there. Concurrently the Eighth Army was to break out of the Pusan Perimeter and move northward, driving the North Koreans into the Inch'on landing forces which would be driving south. Maj. Gen. Edward M. Almond, commander of the newly activated X Corps, was to be in command of the invasion troops.
Early on 15 September a Marine battalion of the let Marine Division (which had loaded in Japan for the Inch'on Landing), covered by strong air strikes and naval gunfire, quickly captured Wolmi Island, just offshore from Inch'on. By afternoon, Marine assault waves rode the high tide into the port itself (UN Offensive-16 September to 2 November 1950). The remainder of the 1st Marine Division disembarked and pressed toward Kimpo Airfield, the Han River, and Seoul. The 7th Infantry Division came ashore; some elements turned southeastward toward Suwon, south of Seoul, while the remainder of the division joined the Marines in the advance toward Seoul. Kimpo Airfield was captured by the 18th, and put in use by the cargo-carrying planes of the Far East Air Forces to augment the stream of supplies being landed by the Navy at Inch'on. The 187th RCT was flown into Kimpo Airfield to strengthen U.N. defenses in that area. After heavy fighting between advancing U.N. forces and the determined North Korean forces, which had resolved to fight for Seoul street by street, MacArthur announced on 26 September that the city was again in friendly hands; but fighting continued there for several days. On 29 September MacArthur returned Seoul to President Rhee in a ceremony held in the blackened capitol building.
The Eighth Army began its offensive northward on 16 September. The ROK I and II Corps were in position on the north side of the perimeter. The U.S. I Corps, composed to the 1st Cavalry Division, the 27th British Commonwealth Brigade, the 24th Division, and the 1st ROK Division, was on the Taegu front. The remainder of the Eighth Army, positioned along the Naktong, included the U.S. 2d and 25th Divisions and attached ROK units. Progress was limited at first, but as the portent of the converging attacks became clear to the North Koreans, they fled north with heavy losses in men and materiel. Elements of the 7th Division (X Corps) and the 1st Cavalry Division (Eighth Army) made contact late on 26 September just south of Suwon, thus effecting a juncture of U.N. forces. Organized enemy resistance continued in the Eighth Army sector until the last days of September. Although large numbers of enemy troops escaped through the eastern mountains, more than 100,000 prisoners were captured during this period; by 30 September the North Korean Army had ceased to exist as an organized force below the 38th parallel. However, remnants of the army, fighting as guerrillas, continued to pose a considerable threat to the security of the U.N. forces.
During the latter part of September the Eighth Army was reinforced by a battalion each of Philippine and Australian troops. Early in October the U.S. 3d Division arrived in the Far East.
Meanwhile Walker's ROK I Corps crossed the 38th parallel on 1 October 1950 and advanced up the east coast, capturing Wonsan, North Korea's major seaport, on 10 October. The R0K II Corps also crossed the parallel and advanced northward through central Korea. In the west, Walker's remaining forces relieved the X Corps in the Seoul area and crossed the parallel on 9 October toward P'yongyang. By mid-October the U.N. forces had penetrated about 20 miles into North Korean territory.
In the second half of October 1950 the advance quickened as enemy resistance weakened and thousands of enemy troops surrendered. U.N. objectives were the destruction of the remaining Communist divisions and the capture of important North Korean cities. ROK troops spread through central and east Korea. Some turned north toward the industrial area centering around Hamhung and Hungnam, others west along the Wonsan-P'yongyang road. In the west the 1st Cavalry Division, after fighting through pill box defenses at Kumch'on, a few miles north of the parallel, progressed up the Seoul-P'yongyang railroad. The 24th Division drove to the south bank of the Taedong River in the vicinity of Chinnamp'o, the port for P'yongyang. The 1st Cavalry and 1st ROK Divisions entered P'yongyang on 19 October and secured the city in the next forty-eight hours. On 20 October the 187th Airborne RCT, complete with vehicles and howitzers, dropped on Sukch'on and Sunch'on, about 30 miles above the city of P'yongyang, to trap North Koreans fleeing northward. In northwest Korea a ROK regiment, leading the advance of the Eighth Army, entered the town of Ch'osan on 26 October, thereby becoming the first U.N. element to reach the Yalu River. Farther south additional U.N. forces crossed the Ch'ongch'on River at Sinanju and pushed toward the Manchurian border. For all practical purposes the North Korean Army had dissolved by the last week in October, and had melted away in the mountains adjacent to Manchuria and the Soviet Union.
Meanwhile Almond's X Corps had been withdrawn from combat and prepared for amphibious landings on the east coast of Korea. Since the rapid advance of ROK ground units and the fall of Wonsan made a combat landing there unnecessary, the 1st Marine Division carried out an administrative landing at Wonsan on 26 October, despite the heavily mined harbor which caused a long delay in unloading. On 29 October the 7th Division landed unopposed at Iwon, 80 miles farther north.
General Almond, adding the ROK I Corps to his command, set out to capture the industrial and communications areas, the port installations, and the power and irrigation plants of northeastern Korea. The ROK I Corps moved up the coastline toward Ch'ongjin, 120 miles north of Iwon. The 1st Marine Division moved 50 miles north of Hamhung and its port of Hungnam, then turned inland toward the Changjin (Chosin) Reservoir, 45 miles to the northwest. Elements of the 7th Division attacked northwestward toward the Pujon Reservoir and the Yalu River.