WASHINGTON — Harold G. Moore Jr., an Army lieutenant general whose leadership in one of the earliest and bloodiest battles of the Vietnam War saved scores of lives and was memorialized in the book ‘‘We Were Soldiers Once . . . and Young’’ and in a film adaptation starring Mel Gibson, died Friday at his home in Auburn, Ala. He was 94.

His family said General Moore suffered a stroke last week but did not provide additional details.

General Moore’s military career spanned three wars and multiple continents, beginning with a posting in Japan during the American occupation after World War II and a stint at Fort Benning, Ga., where he tested parachutes and parachuting equipment on more than 130 test jumps. At least one jump resulted in his being dragged along the ground by an airplane.

Sporting a bulldog face and a Southern accent acquired from a childhood in small-town Kentucky, he developed a reputation as an exceptional combat leader during the Korean War and in the early stages of the Vietnam War — no more so than in the Battle of Ia Drang, the first major engagement between American and North Vietnamese forces.

The battle began Nov. 14, 1965, shortly after General Moore, then a lieutenant colonel, stepped off a Huey helicopter and onto a football field-size clearing in South Vietnam’s Ia Drang Valley. He and the 457 men under his command were there to track North Vietnamese Army units and search for a possible enemy base.

They soon found themselves opposed by more than 3,000 North Vietnamese troops who had been hidden in mountainous terrain alongside the clearing. The American forces’ position, reporters and military historians later wrote, was not unlike that of George Custer, whose troops were surprised, surrounded, and slaughtered at the Battle of the Little Bighorn in 1876.

In the days before the attack, General Moore’s troops sometimes referred to their blond-haired commander as ‘‘Yellow Hair’’ — Custer’s nickname. Sizing up the situation at the clearing, Moore set about avoiding the fate of his predecessor.

Applying a ‘‘first in, last out’’ approach to combat leadership, General Moore led the initial assaults on the North Vietnamese positions himself, and remained at the battle’s front lines until his battalion was relieved after three days of fierce, close-combat fighting.

Joseph Galloway, a reporter for the United Press International wire service who was present for most of the battle, later said that General Moore refused three times to leave the battle and meet with generals in Saigon.

A citation for the Distinguished Service Cross, awarded to General Moore after the engagement, reports that ‘‘throughout the initial assault phase, Colonel Moore repeatedly exposed himself to intense hostile fire to insure the proper and expedient deployment of friendly troops.’’

According to ‘‘We Were Soldiers Once . . . and Young,’’ a nearly blow-by-blow account of the battle that General Moore co-wrote in 1992 with Galloway, 79 Americans were killed and 121 were wounded in the fight. An estimated 1,800 North Vietnamese were killed or wounded.

Lieutenant Colonel Bruce Crandall, who was later awarded the Medal of Honor for delivering crucial supplies of ammunition and water to General Moore’s men, and for flying through smoke and gunfire to ferry wounded soldiers out of the valley, said in a 2007 interview that the battle ‘‘was hell on Earth — for a short period of time.’’

In his book, General Moore credited Huey helicopters, rather than his own tactical skill, for his unit’s survival on the ground. Without helicopters to ferry out the wounded and deliver goods, his men ‘‘would certainly die in much the same way George Armstrong Custer’s cavalrymen died at the Little Bighorn — cut off; surrounded by numerically superior forces, overrun, and butchered to the last man.’’

The book, which also detailed a separate unit’s subsequent, even bloodier engagement at Ia Drang, positioned the monthlong battle at Ia Drang Valley as a pivotal moment in the war’s history, one that convinced US commander William Westmoreland that American forces ‘‘could bleed the enemy to death over the long haul.’’ Vietnamese commanders, it argued, were equally convinced that they could take on American forces, despite their technological superiority.

Widely praised by critics for its research, which included testimonies from US soldiers whom General Moore led and from Vietnamese commanders whom he opposed, the book was subsequently adapted to ‘‘We Were Soldiers,’’ directed by Randall Wallace and with Gibson starring as General Moore.

Harold Gregory Moore Jr. was born in Bardstown, Ky., on Feb. 13, 1922. His father was an insurance agent, and his mother was a homemaker.

General Moore graduated in 1945 from the US Military Academy at West Point, N.Y. He received a master’s degree from George Washington University in 1964 and graduated from the Naval War College that same year.

Following his service in Vietnam, General Moore commanded an infantry division in South Korea and was stationed in the Washington area as deputy chief of staff for personnel at the Army Department.

He retired from the military in 1977.

Beginning in the early 1990s, General Moore returned several times to the battlefield at Ia Drang. Traveling with soldiers who served under him, he made what was perhaps an unprecedented gesture in Vietnam: meeting in person with North Vietnamese commanders who opposed him, and on at least one occasion camping with them at the battlefield under the stars. He chronicled the trips, and lessons learned, in ‘‘We Are Soldiers Still,’’ which was also co-written with Galloway.