Maneuvering
As a first step in the attempt to block and attack the North Korean I Corps, General Matthew Ridgway on March 21, 1951 ordered his own I Corps to move forward to line Cairo, which he extended southwestward across General Lincoln Milburn's zone through Uijongbu (37°43′40″N 127°3′3″E / 37.72778°N 127.05083°E / 37.72778; 127.05083) to the vicinity of Haengju (37°37′49″N 126°46′11″E / 37.63028°N 126.76972°E / 37.63028; 126.76972 (Haengju)) on the Han River. At points generally along this line six to ten miles (10–16 km) to the north, Lincoln Milburn's patrols had made some contact with the North Korean I Corps west of Uijongbu and the Chinese 26th Army to the east. Milburn was to occupy line Cairo on March 22, a day ahead of the airborne landing at Munsan-ni, and wait for Ridgway's further order to continue north.
Requiring Milburn to wait stemmed from Ridgway's not yet having given the final green light to the airborne landing, Operation Tomahawk, as of March 21. Operation Tomahawk would take place only if Ridgway received assurances that weather conditions on March 23 would favor a parachute drop, and that ground troops could link up with the airborne force within twenty-four hours. If these assurances were forthcoming, the 187th Airborne Regimental Combat Team, with the 2d and 4th Ranger Companies attached, was to drop in the Munsan-ni area on the morning of March 23 and block Route 1. Milburn was to establish physical contact with and assume control of the airborne force once it was on the ground. At the same time, he was to open a general corps advance toward line Aspen, which traced the lower bank of the Imjin River west and north of Munsan-ni, then sloped eastward across the corps zone to cut Routes 33 and 3 eight miles (12 km) north of Uijongbu. Once on Aspen, Milburn was to expect Ridgway's order to continue to line Benton, the final COURAGEOUS objective line, some ten miles (16 km) farther north. Reaching Benton would carry the I Corps virtually to the 38th parallel except in the west where the final line fell off to the southwest along the Imjin.
Because the I Corps otherwise would have an open east flank when it moved to line Benton, Ridgway extended its line southeastward into the IX Corps zone, across the front of the 24th Division and about halfway across the front of the ROK 6th Division to a juncture with line Cairo. When Ridgway ordered the I Corps to Benton, General Hoge was to send his western forces to the line to protect the I Corps flank. Meanwhile, in concert with Milburn's drive to lines Cairo and Aspen, General William M. Hoge was to complete the occupation of his sector of line Cairo. Elsewhere along the army front, the X Corps and the ROK III and I Corps remained under Ridgway's order of March 18 to reconnoiter the area between the Hwach'on Reservoir and the east coast. As yet, neither General Edward Almond's patrols nor those of the South Korean corps had moved that deeply into North Korean territory.
The three divisions of the I Corps started toward line Cairo at 08:00 on March 22. The ROK 1st Division, advancing astride Route 1 in the west, overcame very light resistance and had troops on the phase line by noon. The 3d Division astride Route 3 in the center and the 25th Division on the right also met sporadic opposition but moved slowly and ended the day considerably short of the line.
Meanwhile, General Milburn assembled an armored task force in Seoul for a drive up Route 1 to make the initial contact with the 187th Airborne Regimental Combat Team, if and after it dropped on Munsan-ni. Building the force around the 6th Medium Tank Battalion, which was borrowed from the 24th Division of the IX Corps, he added the 2d Battalion, 7th Infantry; all but one battery of the 58th Armored Field Artillery Battalion from the 3d Division; and from corps troops he supplied a battery of the 999th Armored Field Artillery Battalion and Company A, 14th Engineer Combat Battalion. He also included two bridgelaying Churchill tanks from the 29th British Brigade, which had recently been attached to the I Corps. Lt. Col. John S. Growdon, commander of the 6th Medium Tank Battalion, was to lead the task force.
Ridgway made the final decision on the airborne operation late in the afternoon of March 22 during a conference at Eighth Army main headquarters in Taegu. General Partridge, the Fifth Air Force commander, assured him that the weather would be satisfactory on the next day; Col. Gilman C. Mudgett, the new Eighth Army G-3, predicted that contact with the airborne unit would be made within a day's time, as Ridgway required, and also that the entire I Corps should be able to advance rapidly. Given these reports, Ridgway ordered the airborne landing to take place at 09:00 on the following day.
On hearing the final word on the Munsan-ni drop, General Milburn directed Task Force Growdon to pass through the ROK 1st Division on line Cairo early on March 23 and proceed via Route 1 to reach the airborne troops, while his three divisions were to resume their advance with the objective of reaching line Aspen. The ROK 1st Division, which would be following Task Force Growdon, was to relieve the 187th Airborne Regimental Combat Team upon reaching Munsan-ni, and the airborne unit then was to prepare to move south and revert to Eighth United States Army reserve.
Read more about this topic: Operation Courageous