For its part, the 25th Division, commanded by Major General Samuel T. Williams, was to shift over to the I Corps far west coastal area from its own neighboring IX Corps sector on the right. Marine association with the Army division went back to the early days of the war.[410] In August 1950, when the Korean Conflict was then only a few weeks old, the 25th Division, with the 1st Provisional Marine Brigade and the Army’s RCT-5, had spearheaded the first UN counteroffensive on the far southern front, in the Sachon-Chinju area. Now fresh from its own recent period in reserve[411] the 25th Division, including its attached Turkish Brigade, was to take over the 33-mile 1st Marine Division line, effective 5 May. Marine armor and artillery, however, would remain in support of the 25th Division and transfer to I Corps control.
[410] The two divisions had also seen combat together early in WW II, at Guadalcanal. Col R. D. Heinl, Jr. ltr to Dir, MCHist, HQMC, dtd 27 Sep 70, hereafter Heinl ltr.
[411] Soon after assuming command of the Eighth Army, in mid-February, General Taylor had begun to stress the need for a complete eight-week training program for reserve divisions before reentering the line, detailed rehearsal of patrols, and more frequent rotation of artillery battalions to maintain their basic mobility. Hermes, Truce Tent, p. 391.
Another change at this time affected the designation of the United Nations MLR. Called Line JAMESTOWN in the I Corps sector (and variously in other parts of the EUSAK front as MISSOURI, DULUTH, MINNESOTA, and CAT), the Allied front was redesignated simply as “main line of resistance,” beginning 28 April, and was to be so known in all future orders and communications throughout the entire Eighth Army. A further modification dropped the reference “in Korea” from the acronym EUSAK, the title becoming “Eighth U.S. Army.”
In the Marine sector, the last few days of April were a study in contrasts. While Marine frontline infantrymen and cannoneers were having a comparatively peaceful interlude during this period of minimal CCF activity, division engineers were the proverbial colony of beavers. Following up their rigorous schedule in early April of building Freedom Village from scratch within 36 hours, engineer personnel moved out from the division sector late that month to begin construction of the rear area camps that would shortly be occupied by the Marines while in I Corps reserve.
Located approximately 15 miles east of the Marine MLR, the Camp Casey reserve complex consisted of three major areas. They were: the central one, Casey, which gave its name to the entire installation and would house the new division CP and 5th Marines; Indianhead, to the north, where the 7th Marines, 1st KMC Regiment, Division Reconnaissance Company, machine gun and NCO schools were to be established; and Britannia, to the south, assigned to the 1st Marines. Motor transport, engineer, and medical units in support of the respective regiments were to locate nearby.
On 27 April, the day after resumption of truce talks at Panmunjom, Company A engineers began the work of clearing the camp site, erecting prefabricated buildings, and pioneering roads in the 7th Marines northern area. Two days later the 1st KMC Engineer Company was also detailed to Indianhead for work on the 1st KMC Regimental camp. Company C engineers and Company A, 1st Shore Party Battalion, attached to the Engineer Battalion, meanwhile moved into the Casey sector to ready the relocated Division CP and the 5th Marines camp.
Tactical relief of the 1st Marine Division officially began 1 May. By the time it was over, four days later, more than 2,370 truckloads of Marine personnel and equipment had been used in the transfer to Camp Casey. Described another way: if placed bumper to bumper in a continuous convoy, this would have extended more than six miles, the length of the MLR held by a Marine regiment in any major defense sector. As a preliminary step in the relief, on 29 April the division assumed operational control of several incoming Army artillery units (the 8th, 64th, 69th, and 90th Field Artillery Battalions, and the 21st Antiaircraft Automatic Weapons Battalion) plus elements of the Turkish command, including the TAFC Field Artillery Battalion. By midafternoon, the first of the Army infantry relief personnel had also arrived in the division sector, when elements of the three battalions of the 35th Infantry Regiment had reported in to respective 1st Marines[412] host units, preparatory to assuming responsibility for the center sector of the Marine line.
[412] The regiment was newly-commanded by Colonel Nelson, the former UN Personnel and Medical Processing Unit officer, who succeeded Colonel Adams as CO, 1st Marines on 1 May.
On 1 May the 5th Marines, then in reserve at Camp Rose, took over responsibility for the 14th Infantry Regiment, designated as the Army maneuver unit. Later that day, when Colonel Tschirgi’s regiment closed its headquarters and moved out by motor march to Casey, control of the Army unit transferred to the division. The same day, the 1st KMC/RCT artillery battalion—which, like the 11th Marines units, was to remain on line although KMC infantry personnel were to move to I Corps reserve—came under control of I Corps; two days later an Army armored unit, the 89th Tank Battalion, rolled into position in the KMC rear support area and came under division command.