The campaign for Peleliu (code named Operation Stalemate) began in September 1944. The III Amphibious Corps under Major General Roy S. Geiger had responsibility for taking the Palau Islands. These were important to the war effort because the Palaus were Japan’s main bastion in the western Carolinas and only 530 miles from Mindanao in the Philippines. It was Douglas MacArthur’s belief that no invasion of the Philippines could succeed unless the potential enemy threat from the Palaus was eliminated. Admiral Nimitz agreed, adding one additional justification for this operation: Peleliu would provide a base from which the Americans could support MacArthur’s southern Philippines operations.
The actual campaign began on 15 September with the 1st Marine Division poised to strike at the southwest coast of the island. The assault began shortly after dawn and the first waves began coming ashore forty minutes later. The first Marines ashore quickly spread out over the coral sand and set up a defensive perimeter pending the arrival of more troops. The 1st Marines landed in the northern sector, the 5th Marines assumed the center position, and the 7th Marines (less 2nd Battalion, which was held in reserve) took the southern-most beachhead. Colonel Herman H. Hanneken commanded the 7th Marine Regiment.
The 7th Marines came up against heavy enemy fire even before its first landing craft reached the beach; it was a foretaste of what was about to unfold. Intense anti-boat, mortar, and machinegun fire churned through the surf. The intense fire created some confusion within the 3rd Battalion in that some of its elements landed within the sector assigned to the 5th Marines. Once ashore, 3/7 Marines came up against a stubborn force of Japanese defending caves and blockhouses. Major Edward H. Hurst led his Battalion in attacks against the enemy, which the next day resulted in the complete annihilation of a reinforced Japanese battalion of some 1,600 men.
Forward progress ended early on the first day, as the men were set into preparing a defensive perimeter. The 1st Marine Division occupied an area some 3,000 yards in length, and 500 yards in depth. The Japanese launched several counter-attacks during the night; their strongest against 1st Battalion, 7th Marines involving four hours of sustained fighting. The Japanese finally broke contact at around 0600; their attempt to break through the Marine lines had failed. Colonel Hanneken renewed his assault the next day, a drive to secure the southern tip of the island. The sweep continued until the afternoon of the 18th when Hanneken reported the area had been secured.
Once again, the Marines were pissed off at the Japanese defenders. Private First Class Arthur J. Jackson of the 3rd Battalion may have contributed more to the war effort than any other Marine. On 18 September, Jackson virtually became a one-man assault force, storming one Japanese gun position after another. When he was finished being pissed off, Jackson had succeeded in personally wiping out 12 pillboxes, and killing 50 Japanese solders.
“For conspicuous gallantry and intrepidity at the risk of his life above and beyond the call of duty while serving with the Third Battalion, Seventh Marines, First Marine Division, in action against enemy Japanese forces on the Island of Peleliu in the Palau Group, September 18, 1944. Boldly taking the initiative when his platoon’s left flank advance was held up by the fire of Japanese troops concealed in strongly fortified positions, Private First Class Jackson unhesitatingly proceeded forward of our lines and, courageously defying the heavy barrages, charged a large pillbox housing approximately thirty-five enemy soldiers. Pouring his automatic fire into the opening of the fixed installation to trap the occupying troops, he hurled white phosphorus grenades and explosive charges brought up by a fellow Marine, demolishing the pillbox and killing all of the enemy. Advancing alone under the continuous fire from other hostile emplacements, he employed a similar means to smash two smaller positions in the immediate vicinity. Determined to crush the entire pocket of resistance although harassed on all sides by the shattering blasts of Japanese weapons and covered only by small rifle parties, he stormed one gun position after another, dealing death and destruction to the savagely fighting enemy in his inexorable drive against the remaining defenses and succeeded in wiping out a total of twelve pillboxes and fifty Japanese soldiers. Stouthearted and indomitable despite the terrific odds, Private First Class Jackson resolutely maintained control of the platoon’s left flank movement throughout his valiant one-man assault and, by his cool decision and relentless fighting spirit during a critical situation, contributed essentially to the complete annihilation of the enemy in the southern sector of the island. His gallant initiative and heroic conduct in the face of extreme peril reflect the highest credit upon Private First Class Jackson and the United States Naval Service.”
HARRY S. TRUMAN, President of the United States
In the first four days of the battle, the 7th Marines (less 2nd Battalion) had killed 2,609 of the enemy while suffering 47 dead, 414 wounded, and 36 missing in action. But the Marines knew from the Japanese resistance that Peleliu was going to be one hellish battle.
 Roy S. Geiger was a pioneer in Marine Corps aviation. He commanded a Marine fighter squadron in France during World War I, was awarded the Navy Cross for his World War I service, and later commanded a squadron operating in Haiti in the 1920s.
 Hanneken served from 1914 to 1948. He was awarded the Medal of Honor, two Navy Crosses, the Silver Star, Legion of Merit, and Bronze Star medals for conspicuous gallantry on the field of battle. He retired as a Brigadier General. He died in 1993.
 Awarded Silver Star
 Although wounded, Jackson remained with his battalion and ultimately participated in the battle for Okinawa, where he earned a second Purple Heart Medal. He was commissioned as a Second Lieutenant in August 1945 and served in the post-war occupation of China with the 1st Marine Division. Jackson left the Marine Corps to accept a commission in the U. S. Army Reserve, where he served during the Korean War and from which he ultimately retired in 1984.