The third day of November 1942 marked the third day of a combined Marine-Army push to the west along Guadalcanal’s northern coast. Ambitious planners hoped to seize the Japanese base at Kokumbona, but an unexpectedly fierce defense by the Imperial Army’s 4th and 124 Infantry Regiments inflicted heavy casualties and stunted progress. The 5th Marines faced an especially tough challenge from Colonel Nomasu Nakaguma’s 4th Infantry entrenched around the base of Point Cruz. Two days of fierce fighting, including an unusual American bayonet charge, finally trapped the surviving Japanese infantry in a constricted pocket west of the Point. Corporal DeLong helped inspire this charge, shouting “Let’s hit ’em!” and attacking a Japanese cannon, killing the crew, and putting the weapon out of action.
The task of eliminating the final resistance fell to the Second Battalion, 5th Marines, with support from the Third Battalion. Item and King Companies weathered a Japanese bayonet charge at 0630 hours. Between 0800 and noon, the Americans inexorably advanced, compressing the defenders in an ever-shrinking perimeter. The fighting grew desperate and personal at close quarters, with both sides using bayonets as well as bullets. Second Lieutenant Paul Moore (F/2/5) recalled that “The skirmishers went on down to the beach and wound up in a bayonet fight with the Japanese, whom they finally pushed back into the sea. Others were killed. There was a terrible slaughter of Japanese and the battle was finally concluded”.

from Jim McEnery K/3/5, Hell In The Pacific: A Marine Rifleman's Journey from Guadalcanal to Peleliu.
Weldon DeLong started running back and forth with nothing but a pistol and firing whenever he saw a downed Jap make a move. I guess he'd dropped his rifle in the heat of the charge instead of trying to reload. DeLong had put several enemy wounded out of their misery when Slim Somerville spotted three or four Japs hiding in some water behind a log. They thought we couldn't see them, but Somerville noticed their reflections.... "Get down! Get down!" Slim yelled. ...[DeLong] was too intent on looking for Japs to hear Somerville's warning. One of the Japs in the water fired, and the bulled slammed into Delong's chest. He went down without a sound and never moved again. After some other Marines took care of the Japs behind the log, I ran over to DeLong. He was lying in a puddle of blood with his eyes wide open and his pistol still in his hand. The bullet had gone straight through his heart. He was as dead as a man could get.... I felt like someone had kicked me in the gut. DeLong's death left me shaken as bad as I'd ever been. I considered him the best Marine in my former squad and maybe the best in the whole platoon.... One moment of carelessness had cost him his life. He was posthumously awarded a Navy Cross for outstanding valor that day in leading the charge against one of those Jap field pieces and then wrecking the gun. He also had a ship named in his honor. But even more important than that, he was my friend.

DeLong’s body was reportedly buried near where he fell, “in area” or, less helpfully, “Lunga area North Coast Guadalcanal.” He is memorialized at the Manila American Cemetery and Memorial. He was posthumously awarded the Navy Cross and the Purple Heart Medal.

USS DeLong (DE 684) (1943-1946, 1951-1969) was the first ship to be named in his honor.

(Photo and text from the web site, Missing Marines)