MacArthur selected Inchon. Korea's second largest port, it was only 15 miles from the South Korean capital of Seoul. This area was the most important road and rail hub in Korea and a vital link in the main North Korean supply line south. Cutting it would starve KPA forces facing the Eighth Army. Also, Kimpo airfield near Inchon was one of the few hard-surface airfields in Korea, and the capture of Seoul would be a serious psychological blow for the North Koreans.
Planning for chromite began on 12 August. Only MacArthur favored Inchon. The U.S. Joint Chiefs of Staff (JCS) and most of MacArthur's subordinate commanders opposed it. Tidal shifts there were among the highest in the world. At ebb tide the harbor turned into mudflats, and the navy would have only a three-hour period on each tide to enter or leave the port. The channel was narrow and winding, and one sunken ship would block all traffic. There were no beaches, only twelve-foot seawalls that would have to be scaled.
MacArthur overrode suggestions for other sites, and on 28 August he received formal JCS approval for the landing, to be carried out by X Corps. Activated on 26 August and commanded by Major General Edward M. Almond, it consisted principally of Major General Oliver P. Smith's 1st Marine Division and Major General David G. Barr's 7th Army Division. Vice Admiral A. D. Struble commanded Joint Task Force Seven for the landing; Rear Admiral James Doyle developed the landing plan and was second in command.
More than 230 ships took part in the operation. The armada of vessels, carrying nearly 70,000 men, included ships from many countries. Thirty-seven of 47 tank-landing ships (LSTs) in the invasion were hastily recalled from Japanese merchant service and manned by Japanese crews. Planes from 4 aircraft carriers provided air support.
Although loading was delayed by Typhoon Jane on 3 September, deadlines were met. On 13 September the task force was hit at sea by Typhoon Kezia, although no serious damage resulted. The task force reached the Inchon Narrows just before dawn on 15 September, the fifth day of air and naval bombardment by four cruisers and six destroyers.
At 6:33 a.m., as MacArthur observed events from the bridge of the Mount McKinley, the 5th Marines went ashore to capture Wolmi-do, the island controlling access to the harbor. Resistance was light. At 2:30 p.m. cruisers and destroyers began a shore bombardment of Inchon, and at 5:31 p.m. the first Americans climbed up ladders onto the seawall. Fortune had smiled on MacArthur, as the Marines discovered numerous mines at the port waiting to be laid in the water.
The Marines sustained casualties on D-Day of 20 dead, 1 missing, and 174 wounded. The next day as they drove on toward Seoul, Eighth Army began a breakout along the Pusan Perimeter. On 18 September the 7th Infantry Division began landing at Inchon, and on 21 September a remaining Marine regiment disembarked. The Inchon and Pusan forces made contact on 26 September at Osan. Seoul fell on the afternoon of 27 September.
Victory in the Inchon-Seoul campaign greatly increased MacArthur's self-confidence. He believed that the KPA was so badly beaten that the war for Korea had been all but won and was just a matter of mopping up, an assessment that proved grossly incorrect.
Spencer C. Tucker
Heil, Robert Debs, Jr. Victory at High Tide: The Inchon-Seoul Campaign. Baltimore: Nautical and Aviation Publishing Company of America, 1979.; Montross, Lynn, and Nicholas Canzona. U.S. Marine Corps Operations in Korea, Vol. 2, The Inchon-Seoul Operation. Washington, DC: Historical Branch, USMC, 1954–1957.