Detachment X, thirty-five men of the 507th Antiaircraft Artillery Automatic Weapons Battalion, was the first US ground force unit to arrive in Korea. Within a short time the detachment shot down a Yak fighter with quad-fifty caliber machineguns, suffering five wounded in the action.
Therefore the White House authorized the transfer of a contingent of U.S. troops-men of the 507th Antiaircraft Artillery Battalion - to Korea. They were told to hold Suwŏn airfield while other American soldiers and sailors secured fields and docks in the vicinity of Pusan, on the southeast tip of the Korean peninsula. A deadly sequence was forming. Once aircraft are committed,. they must have airstrips. Airstrips need ground crews, and these crews have to be protected by U.S. infantry. The same pattern would emerge later in Vietnam