“Every Marine a rifleman is a mantra that has been engrained in our warrior ethos since the first day we aspired to be Marines. This aspect of our Corps sets us apart from other branches of Service who delineate themselves by occupational specialty or demonstrate allegiance to a specific unit through the wearing of a patch or symbol. The only symbol we as Marines recognize is the Marine Corps emblem. We are united not only by this iconic emblem but also by the shared experience of the training we all endure aimed at achieving proficiency as warfighters first; everything else is secondary. Examples of the execution of that concept are a testament to the continuing exceptionality of the Marine Corp.”
—James H. Ferguson, First Lieutenant of Marines
Skill with weapons of war is the hallmark of the United States Marine Corps and the development and maintenance of these skills has been emphasized by Marine leaders since the Corps’ earliest days. This emphasis and proficiency is how Marines win America’s battles. Because the Marine Corps has never been a large service, it is necessary that every Marine —no matter what his military occupational specialty— is able to perform the duty of an infantryman. Any Marine who is unable to qualify with his service rifle is useless to the Corps.
Nowhere was the skill of warfare more critical to the survival of Marines than the Battle of Chosin Reservoir, North Korea, October – December 1950.
Subsequent to the successful landing at Inchon and the retaking of the capital of South Korea, General of the Army Douglas McArthur attached the First Marine Division to the X Corps  and ordered them to make another amphibious landing —this time, on the eastern side of the peninsula at a place called Wonsan. There was not much time from October 7, 1950 to re-load amphibious shipping for this landing, but all Marines turned to. In MacArthur’s mind, it was critical to provide a blocking force to prohibit the escape of fleeing remnants of the beaten North Korean Army.
As it turned out, the Wonsan landing was unnecessary. The Eighth Army quickly advanced to seize the North Korean capital of Pyongyang; on the east coast, two Republic of Korea divisions temporarily assigned to X Corps occupied Wonsan without any resistance. The Marines came ashore unopposed on 25 October 1950.
During the unloading, Marine Corps Shore Party units assumed responsibility for the beaches.  At the outset, the Marines encountered difficulties from offshore sandbars. Tractors were marshaled to pull wheeled vehicles to high ground, and the beach had to be sculpted with ramps to facilitate unloading from small boats. No matter the difficulties, the Marines plugged away even to the extent of using floodlights for cranes during hours of darkness. In spite of the lack of armed opposition, Shore Party Marines took no chances: they set up a defensive perimeter on the exposed flank of the southern beach.
After six days of unremitting effort, the First Marine Division was finally ashore. Stacked along the shore stood 18,000 tons of supplies and equipment, and nearly 5,000 vehicles. A week later, the Shore Party Battalion was placed under the operational command of X Corps and ordered to unload the Third Infantry Division.
First Engineer Battalion was at the same time employed in every conceivable combat engineering task, from saw mill operations, repairing railways, converting railway passenger cars to accommodate wounded personnel, and repairing or constructing bridges and air strips. Potable water points were established, tons of enemy ammunition exploded, and the Division command post and nearby hospital at Hamhung was wired for electricity.
The combat engineers also doubled as infantry. On 3 November 1950, the Seventh Marines engaged a Chinese Communist division while en route to Hagaru-ri. A squad of combat engineers filled a gap in the line at a critical moment … it was only one of many engagements involving Marines of the First Engineer Battalion.
The combat engineers worked steadily to improve the main supply route (MSR) from Hamhung to Hagaru-ri; they did this while exposed to the possibility of enemy snipers or substantial attack. What they knew, and what every Marine assigned to the First Marine Division knew, was that no one on MacArthur’s staff in Tokyo or at the Joint Chiefs of Staff in Washington had a clue about what was really unfolding in Korea. Not even the X Corps command, Major General Edward M. (Ned) Almond.  Even though the Chinese withdrew after their first engagement with the Marines, the Marines knew —because all intelligence seemed to indicate— that the Chinese had entered the conflict. The Marines needed their tanks; combat engineers made sure that the roads were suitable to accommodate them.
Marine engineers and tank officers found the MSRs uninspiring. From the railhead at Chinhung-ni all the way to the Chosin Reservoir the road presented a series of sharply winding curves atop narrow shelves —cliffs on one side of the road, and deep chasms on the other. It was not the ideal terrain for fighting a determined enemy. Combat engineers widened and reinforced the roadway; a great deal of attention was directed to bridges, bypasses, and culverts. The task was so critical that Major General Oliver P. Smith (Commanding General, First Marine Division) pulled combat engineers away from other tasks so that they could concentrate on the MSR.
By mid-November, Chinese Communists were not the only enemy: cold weather was setting in. I do not mean the kind of cold weather one might find in Indiana; it was cold weather of the frigid north. The only way to break the frozen soil was by bulldozers, but even then the freezing cold demanded innovation from these Marines —including the use of carbide to jury-rig fiercely hot furnaces that kept the water from freezing, which enabled Marine engineers to construct piers. The engineers also found good uses for enemy munitions left behind in their efforts to improve the MSR.
The first Marine tanks traveled from Chinhung-ni to Hagaru-ri on November 18; on that same day, Marine engineers began constructing a landing strip suitable for C-47 aircraft at Hagaru-ri. Combat logisticians began pushing supplies forward to Hagaru-ri as General Smith anticipated Communist Chinese attacks upon forward units. The strip was ten percent complete by the twenty-second of November, but the temperatures made in nearly impossible for bulldozers to penetrate the granite-like earth. Another example of innovative Marines was that the combat engineers paused long enough to weld steel teeth rippers to the blades of the bulldozers. This did work for a while, but the earth froze to the cutting edges, and this required the Marines to use air compressors and jack hammers to remove the frozen soil.
Under these circumstances, it is not remarkable that the Marines had completed less than fifteen percent of the airstrip when the Chinese attacked in full force. What is amazing is that within only ten days, the Marines had transformed permafrost into an operative landing strip suitable for C-47 aircraft. It was the result of these efforts that hundreds of frostbitten and wounded Marines and soldiers of the Seventh Infantry Division were evacuated by air. The C-47 pilots of the United States Air Force deserve credit for their skill and daring during this massive effort to save the lives of our troops. The combat engineers had scraped out an inadequate strip, the air control mechanisms were crude in the extreme, but not a single plane was lost during the effort.
I want to spend some time on the Air Force effort to support forward deployed soldiers and Marines.
When the Chinese attacked the UN Forces in North Korea, they did it with 18 infantry divisions approximating 150,000 men. They cut the single road that ran south from the Chosin by destroying a road bridge near the hydroelectric dam near Koto-ri. Their intention was to deny any escape to soldiers and Marines. Since the Marines could no longer push their resupply forward on land, C-119 “Flying Boxcar” aircraft of the U.S. Air Force Far East Combat Cargo Command, which included the 314th Troop Carrier Group, airdropped ammunition, rations, and fuel to the soldiers and Marines of X Corps.
At this point, the temperature in North Korea registered minus 35 degrees Fahrenheit.
The Chinese may have imagined that they had the Americans boxed in, but General Smith contacted the Far East Combat Cargo Command requesting aerial delivery of a replacement bridge. This was a feat that had never been achieved. What was needed were four M-2 Treadway Bridges; Smith requested eight.
On Dec. 6, 1950, the Air Force made a trial drop of a single 4,000-pound M-2 from a C-119 at Yonpo airfield in North Korea. The test drop took place at an altitude of 800 feet and flying at 140 knots. Five of the six parachutes failed to open and the bridge span fell to earth like a brick. With no time left for further tests, parachute riggers configured eight Treadway Bridge sections, each with larger cargo parachutes, and loaded the 4,000-pound items onto eight C-119s from the 61st Troop Carrier Squadron.
The following day, three of the loaded C-119s took off from Yonpo airfield five minutes apart. The first three bridge sections were dropped successfully from 800 feet at 120 knots on a drop zone a half-mile north of Koto-ri. The next five C-119s then took off from Yonpo airfield and successfully dropped their bridge sections on a UN drop zone one mile southwest of Koto-ri. Six of the eight bridge sections landed undamaged within the small drop zones, one was damaged as it collided with earth, and one fell into Chinese-controlled territory.
After clearing the surrounding slopes of Chinese troops, Marine Corps combat engineers immediately used four of the eight Treadway Bridge sections to repair the bridge across the 1500-foot-deep gorge at Koto-ri. The MSR was reopened on December 9, 1950. Within three hours, thirty thousand American troops began their march to Hungnam. They took with them all their vehicles, all of their wounded, and all of their dead.
The Chinese renewed their efforts to stop them. In this process, the Chinese gave up nine infantry divisions to withering Marine air and ground firepower. Service troops from more than 30 non-infantry units fought alongside the First Marine Regiment, commanded by Louis B. “Chesty” Puller. Some of the engineers took part as infantry, and others continued to work on the airfield even as they became targets for enemy snipers.
The Marine defense of Hagaru-ri provided a base for the Fifth and Seventh Marine regiments when they cut their way through from Yudam-ni. During this march, combat engineers were often on the point using bulldozers to remove wrecked vehicles, destroying enemy roadblocks, or constructing bypasses. Combat engineers also engaged in fighting during the march from Hagaru-ri to Hamhung. At the last moment, they added another 300 feet to the landing strip at Koto-ri —they did this while under fire and frigid conditions.
In combat, every Marine a rifleman. It was true at the Chosin Reservoir and it remains true today.
 X Corps consisted of two regiments in the Third Infantry Division, an emaciated, inexperienced, and poorly led Seventh Infantry Division, and the U. S. Marine Corps’ First Marine Division.
 Marines assigned to shore party units are responsible for organizing beach areas during an amphibious landing. They perform a function similar to Navy Beach Masters. In World War II, shore party Marines were assigned to Pioneer Battalions, along with combat engineers, and heavy equipment operators. Subsequently, these became separate battalions within the framework of an infantry division.
 General MacArthur set into motion a very unusual (some might even argue inept) command relationship by assigning Ned Almond to command X Corps. While in this capacity, he also served as MacArthur’s Chief of Staff in Tokyo. When Almond should have been reporting to the Commander of the Eighth Army, Almond ignored Lieutenant General Walker; he ignored the X Corps as well. Major General Smith and his staff did most of the planning, and the primary military leader of X Corps was General Smith.