At dawn on 25 June 1950, the North Korean People’s Army (NKPA) unleashed massive artillery fire into the Republic of (South) Korea (ROK). On the heels of the barrage, the NKPA invaded the ROK with a force of 135,000 troops organized into eight infantry divisions, 24 artillery regiments, 120 Soviet T-34 tanks, five constabulary brigades, and 180 Soviet aircraft.
Understandably, the South Korean people were terrified, illustrated by a massive surge of refugees heading south from Seoul to safer locations. However, they wouldn’t find any haven because the NKPA seized the ROK capital in two days and then continued their attack south. The communists intended to seize the entire Korean peninsula. Thousands of refugees preceded the NKPA forces — their legs moving as fast as possible to escape the slaughter. The people were terrified, and by mid-July 1950, the United States and South Korean governments had done nothing to allay those fears.
The U. S. Army occupation forces stationed in Japan did what they could to stop the invasion, but they were young soldiers, untrained, inexperienced, inadequately equipped, poorly led, and sent to confront the NKPA in insufficient strength to stop the onslaught. Throughout July, US Army forces experienced one defeat after another. In time, victory over the Americans is what the NKPA commanders came to expect.
Every day, thousands of refugees streamed into the southeastern city of Pusan, seeking protection. For the most part, the South Korean refugees were simple people. They didn’t understand any of the reasons for this sudden war. What they did know was that their lives were in jeopardy. They had witnessed the NKPA’s ruthlessness; they had seen American Army slaughtered and overwhelmed. The fear among the refugees was palpable. One American journalist noted that in Pusan, one could almost smell the fear in the people — their panic worsening with each passing day.
But then, beginning in the late afternoon of 2 August 1950, a remarkable and easily observable transition began taking shape. American ships began arriving in the port city of Pusan. The word went out. These ships were carrying United States Marines. People started crowding around the docks; they wanted to know more. Unloading operations began as soon as the ships tied up along a pier.
Early the next morning, Marines began to form upon the pier. They were dressed in combat uniforms, were well-armed, and carried field packs on their backs. There were close to 5,000 men when assembled—a color guard formed in front of the Brigade. A large crowd of Korean civilians stood back and observed the goings-on. The Koreans no doubt wondered if these soldiers would save them; they may have noted that if any of these American Marines were fearful, it didn’t show in their demeanor or expressions. Word quickly spread throughout the city. There was still hope.
Although the average age of these young men was only 19½ years, they exuded discipline, confidence, and determination. There was nothing timid about these youngsters; they understood their mission: find the enemy and kill him. It didn’t take long for NKPA commanders to realize that the tide was turning against them.
While company and platoon officers and NCOs mustered Marines on the pier, their Commanding General, Brigadier General Edward A. Craig, concluded his meeting with his subordinate commanders and senior staff. Colonel (select) Raymond L. Murray commanded the 5th Marine Regiment. Lieutenant Colonel George Newton commanded 1st Battalion; Lieutenant Colonel Harold Roise commanded 2nd Battalion, and Lieutenant Colonel Robert Taplett commanded 3rd Battalion. Craig issued his “commander’s guidance” (See also: The Fire Brigade), concluding with this strict admonition:
“The Pusan perimeter is like a weakened dike; the Army intends to use us to plug the holes as they open. We’re a brigade —a fire brigade. It will be costly fighting against a numerically superior enemy. Marines have never lost a battle; this Brigade will not be the first to establish such a precedent. Prepare to move.”
Within an hour, the Marines of the 1st Provisional Marine Brigade were en route toward a small town named Chang-won, the designated assembly area for the Eighth US Army reserve.
The Tactical Situation
The Battle of Osan was the first significant US engagement inf the Korean War. Headquarters, Eighth U.S. Army, ordered Task Force Smith (1st Battalion, 21st Infantry Regiment (reinforced)) (1/21 INF) to set up a blocking position against an overwhelming NKPA force on 5 July. It was an unreasonable assignment and failed to slow the NKPA assault for more than a couple of hours. Task Force Smith suffered 180 dead, wounded, scattered, and/or captured. NKPA soldiers bound some of the American prisoners with their hands behind their backs and then executed them.
As elements of the 24th Infantry Division (24 ID) arrived in Korea from Japan, the NKPA continued to press south, pushing American and South Korean forces back at Pyeongtaek, Cho-nan, and Chochiwon. At the Battle of Taejon, 24 ID suffered 3,602 dead and wounded. Nearly 3,000 U.S. soldiers were taken, prisoner. The NKPA continued their attack.
By the time the Marines arrived on 2 August Eighth Army’s position was unsustainable. US/ROK forces occupied a tiny section of the Pusan Perimeter’s southeast corner. General Walton H. Walker, commanding the Eighth Army, had traded space for time. All that remained in US hands was a small sector 90 miles long and 60 miles wide. General Douglas MacArthur, Supreme Commander of the Allied Powers (SCAP), ordered soldiers in by the thousands. Not only did Walker need fighting units, but he also needed replacements for the dead and wounded. The first to arrive included the 1st Cavalry Division (1 CAV), 2nd Infantry Division (2 ID), and 25th Infantry Division (25 ID).
Walker faced two critical challenges. First, because replacements were arriving in piecemeal fashion, General Walker could only plug them into units positioned at critical junctions. They could not attack the enemy; they could only hold these key positions — and even that was dicey. The second problem was that Walker’s reinforcements, while fresh from stateside or territorial commands, were still only minimally trained. Most of these men had no previous combat experience. Walker worried because if the Eighth Army lost the Pusan Perimeter, there would be no way to land further replacements or supplies — and no way to withdraw any survivors.
The Battle for Hill 342
General Walker designated the 25th ID as Task Force Kean, after the division commander, Major General William B. Kean. Walker assigned Craig’s Brigade to reinforce Task Force Kean. Kean’s subordinate units included the 24 INF, 27 INF, 35 INF, and the 5th Regimental Combat Team (5 RCT).
On 6th August, Colonel Murray led his 5th Marines toward Chindong-ni. General Kean intended to replace the 27 INF with the 5th Marines. Lieutenant Colonel Taplett’s 3/5 (reinforced) moved toward Changwon to replace 2/27 INF on the line two miles outside Chindong-ni, where the road to Mason takes a sharp northward turn into the village of Tosan.
Taplett effected the relief of 2/27 INF within two hours, establishing his command post (CP) on the first step of Hill 255 co-located with Weapons Company, 3/5. Temporarily under the operational control of HQ 27 INF, Taplett answered to Colonel John H. Michaelis, the army regiment’s commander. Taplett’s mission was to provide a blocking force; he needed a tight defensive line to do that.
Lieutenant Colonel Taplett ordered Captain Fegan to set in his Company H (How Company) above his CP to have a good field of observation of enemy movements. Taplett directed First Lieutenant Robert D. Bohn, commanding Company G (George Company), to set in two rifle platoons on Hill 99, situated west of Hill 255, and one platoon on a small knoll at the base of Hill 255.
Lieutenant Bohn directed the 1st Platoon to take the knoll position. Commanding 1st Platoon was Second Lieutenant John J. H. Cahill, USMC. Cahill’s platoon was reinforced by a 75mm recoilless rifle platoon.
The six platoons of George and How companies shared a tactical area of responsibility (TAOR) extending some 3,000 yards. Taplett’s only reserve force consisted of the headquarters element. Shortly after midnight on 7th August, Colonel Michaelis ordered Taplett to dispatch a rifle platoon to reinforce Baker Company, 1/27 INF atop Hill 342. Taplett contacted Colonel Murray (CO, 5th Marines) to argue that he could ill-afford lose one-sixth of his infantry force. Murray explained that General Dean had ordered Hill 342 held at all costs, and Taplett must provide the platoon.
Taplett assigned the mission to First Lieutenant Bohn; Bohn tasked Blackie Cahill.
Hill 342 was a massive molar-shaped structure rising steeply from the MSR west of Chindong-ni, extending northward 2,000 yards to another hill mass that was nearly 2,000 feet in elevation. Elements of the NKPA 6th Infantry Division occupied the second hill mass. The terrain was steep, the footing unsure, and the hillside inundated with shrub vegetation. Before leaving 3/5’s perimeter, Taplett ordered Cahill reinforced with a machinegun squad and a radio operator. None of Cahill’s men had more than a couple of hours of rest before embarking on this relief mission.
There was one minor glitch: Cahill reached Colonel Michaelis’ CP near a bridge south of Hill 99 at around 03:00. Michaelis being absent, the regimental operations officer directed Cahill to proceed 700 yards further down the MSR and reported to the CO 2nd Battalion, 5 RCT (2/5 RCT), whose CP was located just north of the MSR at the tip of Hill 342’s eastern-most base. The Army operations officer informed Cahill that he wasn’t reinforcing Company B; he was replacing it. 27 INF needed this rifle company as part of General Kean’s reserve force. 5 RCT could not relieve Company B because 5 RCT was scheduled to begin an offensive within a few hours.
2ndLt Cahill no doubt wondered how a rifle platoon could realistically replace an infantry company, but Cahill was a combat veteran, and he made no bones about it. After a quick briefing by an operations officer at 2/5 RCT’s CP, a guide led Cahill and his platoon northward, skirting the western base of Hill 352. A few hundred yards along, the army guide discovered that he had lost his way in the darkness. A few enemy artillery shells landed nearby, but there were no casualties. When Cahill’s column reached the end of the valley, rifle fire erupted, wounding two Marines. The army guide advised Cahill that he should not begin his climb until dawn because of the slippery footing and the nervous condition of Baker Company’s soldiers. At 0500, Cahill’s Marines had marched 3 miles from Hill 99.
At dawn, Cahill realized that the earlier rifle fire had come from soldiers of 2/5 RCT, spooked by the Marine’s movements in the pitch-black early morning hours. Cahill took the lead in the climb. At first, the Marines made good progress, but the heat soon became a war-stopper. The temperature was around 112 degrees. Cahill’s Marines began gasping for air, sweating profusely, and stumbling on the steep, slippery pathways. For every five steps upward, they slipped back three. Water discipline collapsed, and canteens soon emptied. It wasn’t long before Cahill’s Marines began collapsing from heat exhaustion, and some of these young men lost consciousness — they were on the verge of having a heat stroke. Cahill’s platoon became a ragged file, but as Cahill’s NCOs urged the men forward, Cahill increased his pace and proceeded to the crest of the hill.
Cahill finally reached Hill 342’s summit at around 08:30, where he met the Army company commander. The captain began briefing Cahill on his company’s defensive positions. Baker Company, he explained, had been under continuous enemy fire within their triangle-shaped perimeter. All three of the Company’s platoons were shattered. Just as Cahill’s platoon began straggling into the army perimeter, NKPA forces opened fire from well-concealed positions from an adjacent hill. Cahill’s NCOs quickly set the Marines into firing positions. So far, Cahill had lost one man killed, six others wounded. Considering both combat and heat casualties, Cahill’s 52-man platoon at the base of Hill 342 had only 37 effectives at its summit. NKPA intensive fire had a demoralizing effect on the soldiers, and it was all the unit’s officers could do to keep them in their defensive positions. In a brilliant move, Cahill suggested to the Army commander that he set Marines into positions among the soldiers. Cahill understood service rivalry; knowing that the soldiers and Marines were eyeing one another, service pride kicked in, and the troops on the line, both Army and Marine, settled down to the business at hand. Cahill lost two additional Marines to enemy fire as his NCOs were setting them into position.
Improvise — Adapt — Overcome
At noon, several companies of NKPA troops assaulted the summit of Hill 342 supported by intense machine gunfire. Despite the onslaught, Marines and soldiers delivered well-aimed return fire. However, the situation was desperate, and Baker Company was ordered by 5 RCT to remain in-place until a larger force of Marines could relieve them. 2ndLt Cahill used his radio to call in Army artillery support to silence enemy mortars. As the artillery unit registered its fires, Cahill looked for and spotted an enemy, forward observer. Yet, despite the artillery battery’s accurate barrage, NKPA mortars continued to rain down on the soldiers and Marines. Then, with water and ammunition becoming in short supply, Cahill radioed in for an airdrop. Within a short time, a USAF R4D flew over Hill 342 and dropped badly needed ammunition and water — the resupply landed amid the enemy positions.
Cahill was back on the radio in short order. 1stMarBde handed the resupply mission to Marine Observation Squadron (VMO)-6, whose OY-2 aircraft dropped ammunition and water inside the Baker Company perimeter. But, as the water cans hit the earth, most exploded, and the Marines and soldiers had to make do with only a few mouthfuls of water each. Cahill’s Sergeant Macy volunteered to lead a patrol in search of water. With permission granted, Macy and a few volunteers descended the southeastern slope under enemy fire, lugging 5-gallon cans along with them. Meanwhile, the NKPA was working to surround and cut off Hill 342
While Cahill was making his way toward Hill 342, the rest of Taplett’s 3/5 (set in along the base of Hill 255) came under enemy mortar fire beginning at around 02:30 on 7 August. Taplett was anxious about the situation with Cahill, but there was nothing he could do about it until sun up.
At around 02:00, Lieutenant Colonel Roise’s 2/5 began moving by truck to its terminus at the base of Hill 255. NKPA delivered devastating mortar fire. Roise was fortunate to lose only one Marine killed and eleven wounded — including Captain George E. Kittredge, the CO of Easy Company, 2/5. Once 2/5 arrived in the vicinity of Hill 255, operational control of 2/5 and 3/5 reverted to Colonel Murray. Murray ordered Roise to occupy Hill 99. After repositioning 1/5, George Company 3/5 rejoined Taplett’s main body.
General Keane planned for 5 RCT to begin its assault at 0500, but the advance was stopped cold in the first hour. The NKPA were not particularly impressed with Kean’s assault; they launched an attack of their own. Cahill’s fight on Hill 342 constrained the entire 2nd Battalion, 5 RCT, in its attempt to hold open the Chinju Road. Attaching Cahill’s platoon to Baker Company — and leaving the army company in place — was helping to do that, but the 5 RCT’s second battalion was temporarily lost to the regiment.
General Keane was desperate. He ordered Murray to provide a battalion to relieve 2/5 RCT, and the mission assigned to 1/5. Colonel Roise’s mission was to relieve the army battalion and clear the area of enemy forces. Keane then ordered Craig to assume command of all forward units in the Chindong-ni area.
When 2/5 reached the base of Hill 342, Colonel Roise ordered Dog Company to ascend the north fork toward Hill 342’s eastern spur and seize both the spur and the great hill. First Lieutenant William E. Sweeney, newly appointed commander of Easy Company, was ordered to pass behind Sangnyong-ni and seize the western spur. It was a wide dispersal of a light battalion, but Murray needed Roise to protect the valley between the two spurs and this was the only way he could do it. The CO of D Company was Captain John Finn. As the company ascended Hill 342, the Marines, having spent a sleepless night, began to experience the effects of rapidly increasing heat. Thirty minutes into the climb, Finn’s Marines encountered rifle and machine gun fire. Roise’s Operations Officer, Major Morgan J. McNeely, had previously told Finn that he would encounter no organized enemy resistance. The constant chatter of Chinese-made burp guns proved McNeely wrong.
Finn called together his platoon commanders, assigning each a route to ascend Hill 342. 2nd Platoon, under Second Lieutenant Wallace J. Reid, was ordered to push through Taepyong-ni and begin his climb at its juncture with the spur. Second Lieutenant Edward T. Emmelman would lead his 3rd Platoon to the top of the spur from the left. Second Lieutenant Arthur A. Oakley, commanding 1st Platoon, would hold the right flank and ascend the southern slope of Hill 342. Enemy opposition was scattered, but before Dog Company reached the crest of the spur, five Marines had received gunshot wounds. As with Cahill’s Marines, Captain Finn’s men were suffering the effects of heat exhaustion in the triple-digit heat.
Captain Finn ordered his executive officer (XO), First Lieutenant Robert T. Hannifin, to establish the company headquarters and mortar section on the high ground directly above Taepyong-ni. At dusk, Dog Company was still several hundred yards from the summit of Hill 342. Finn radioed Roise for permission to rest his men for the night. While Finn was communicating with Roise, 2ndLt Oakley climbed to the summit and contacted Cahill and the Baker Company commander — both of whom accompanied Oakley to Finn’s position. The Army CO advised Finn to remain in place until early the next morning and Roise agreed.
During the early morning hours of 8 August, NKPA troops covertly approached the perimeter of Hill 342. At first light, the enemy assaulted the crest of the hill. The fight turned into a gruesome hand-to-hand struggle. Soldiers and Marines repelled the attack, but not without taking serious casualties. One Marine died from gunshot and bayonet wounds. Captain Finn’s three platoons assaulted the hill, brushing aside enemy resistance and joining what was left of Baker Company and Cahill’s platoon. While effecting the relief, NKPA rifle and automatic weapons punished the perimeter with intensive fire.
Once Dog Company was in possession of the summit perimeter, Baker Company and Cahill’s Marines descended the hill. Cahill had lost one-third of his men. Captain Finn fared no better. NKPA fire killed several of his men while setting in their defenses, including 2ndLt Oakley and 2ndLt. Reid. 2ndLt Emmelman received a serious head wound. As Captain Finn moved forward to recover Reid’s body, he too was struck in the shoulder and head.
First Lieutenant Hannifin, assigned to direct the company headquarters and mortar platoon, moved forward to join the rest of Company D at the summit. Just below the summit, he encountered the First Sergeant, who was helping to evacuate Captain Finn. Hannifin learned that he was now the CO of Dog Company. He was also the only officer remaining alive in the company. In the absence of officers commanding platoons, the NCOs stepped up.
1stLt Hannifin reached the summit of Hill 342 with just enough time to organize the defenses and set in his mortars before the NKPA initiated a second attack. The Marines beat back the assault, killing dozens of the attackers, but the company had lost and additional six killed and 25 wounded. While speaking with Roise on the field radio, Hannifin collapsed due to heat exhaustion. Master Sergeant Harold Reeves assumed command of Dog Company. Second Lieutenant Leroy K. Wirth, a forward observer from 1/11 assumed responsibility for all supporting arms, including aircraft from MAG-33 circling overhead. Both Reeves and Wirth exposed themselves to enemy fire by ranging forward to call in airstrikes and reassess their tactical situation.
Easy Company 2/5 moved forward along the western spur of Hill 342 and dug in. Colonel Roise dispatched Captain Andrew M. Zimmer, who was serving as 2/5’s assistant operations officer, to take command of Dog Company. NKPA forces continued to harass Zimmer’s Marines at the summit, but because the enemy had taken a massive number of casualties in the fight, they gave the Marines of Dog Company a wide birth.
Major Walter Gall, commanding Weapons Company 2/5, dispatched a combat patrol to eliminate NKPA machine guns in Tokkong-ni. Unable to dislodge the communists, the patrol returned to Gall and briefed him on the enemy situation. With this information, 1stLt Ira T. Carr unleashed his 81mm mortar section and all enemy activity in Tokkong-ni ended.
On the afternoon of 9 August, an Army unit relieved Dog Company at the summit and 2/24 INF relieved Roise’s 2/5 of its responsibility for Hill 342. Documents later retrieved from enemy dead revealed that the NKPA forces engaged with soldiers and Marines at the summit were members of the 13th and 15th Regiments of the NKPA 6th Infantry Division. Cahill reported a conservative estimate of 150 dead communists in the hill fight, in total around 400 enemy KIA, but the actual number is unknown. What is known is that between 500 to 600 communist troops challenged the Marines and soldiers to the right to possess Hill 342 — and lost.
For his effort atop Hill 342, then Second Lieutenant Blackie Cahill received the Silver Star medal and a Purple Heart. The courageous Marine officer would later receive three additional Purple Heart medals and the Bronze Star.
- Appleman, R. E. South to the Naktong, North to the Yalu. Washington: Department of the Army, 1998.
- Catchpole, B. The Korean War. London: Robinson Publishing, 2001.
- Geer, A. The New Breed: The Story of the U.S. Marines in Korea. New York: Harper & Bros., 1952.
- Hastings, M. The Korean War. New York: Simon & Schuster, 1988.
- Varhola, M. J. Fire and Ice: The Korean War, 1950-1953. Mason City: Da Capo Press, 2000.
 Sixty-five percent of the Brigade’s officers and NCOs were combat veterans from World War II.
 Bob Taplett (1918-2004) served with distinction as a Marine officer for twenty years, serving in World War II and the Korean War. He was awarded the Navy Cross and two awards of the Silver Star medal in recognition of his courage under fire. Retiring in 1960, Taplett authored an autobiography titled Darkhorse Six, which was published in 2003.
 Hill 342 stood 342 meters above sea level (1,122 feet), a substantial climb in full combat gear in 112° temperatures.
 General Kean’s plan was to withdraw 27 INF to serve in division reserve, replacing it with 5th Marines. The Army’s 5 RCT would serve on the Marine’s right flank.
 The 5th Marines, hastily formed for combat duty at Camp Pendleton, departed California on 7 July. The regiment was understrength. Typically, a Marine infantry battalion consists of an H&S Company, Weapons Company, and three rifle companies. This is the standard configuration for a maneuver unit. In July 1950, Murray’s battalions consisted of an H&S Company, Weapons Company, and two rifle companies. These personnel shortages were the result of President Truman’s scheme to gut the U.S. military following World War II.
 Second Lieutenant John J. H. (“Blackie”) Cahill (1924-2005) served in the U. S. Marine Corps (1939-1974). There is not much that we know about Cahill, beyond the fact that he likely served aboard ship during the New Guinea campaign, later participated in the island campaigns of the Gilbert Islands, at Cape Gloucester, Peleliu, and Okinawa as an enlisted Marine. He may have left active service at the end of World War II to attend college. In 1950, Cahill was a 2nd Lieutenant with Company G, 3rd Battalion, 5th Marines during the battle for Pusan. He later served with the 5th Marines at the Chosin Reservoir. He later served three tours of duty in Vietnam, notably at the Battle of Khe Sanh when he commanded 1st Battalion, 9th Marines. Cahill’s twin brother Vincent also served in World War II in the Army Air Corps. Colonel Vincent S. Cahill retired from the U.S. Air Force in 1976.
 The 75mm Recoilless Rifle was a tripod-mounted weapon weighing 114.5 pounds. It fired HE, HEAT, and WP rounds, had a range of 7,000 yards, and was effective against T-34 tanks within 400 yards. A RR platoon consisted of four rifles/14 Marines.
 Every Marine, regardless of MOS, is a qualified infantry rifleman.
 General Craig was underwhelmed with 5 RCT’s performance; there was, in his opinion, no good reason for the army regiment’s lack of advance — except that the forward area was confused. In the one-lane dirt roads, military traffic had jammed the MSR and none of the US forces could advance or withdraw. Craig realized that the slowness of the 5 RCT’s advance had opened the door to the NKPA, which had launched its own attack.