William Manchester, 82, whose riveting books about men in military and political life made him one of the greatest popular historians of the 20th century, died June 1 at his home in Middletown, Conn.

His slow death, after two strokes, brought a poignant end to one of the most productive and scrupulous writers of best-selling tomes about outsized modern historical figures and contemporary culture.

Fueled by yogurt and brief naps in his office, the sinewy Mr. Manchester could withstand 50-hour writing sessions in his heyday. In recent years, he was grief-stricken by his inability to concentrate even on simple television programs, much less his final, three-volume project, a biography of Winston Churchill. He had to relinquish control of his career-capping work.

"Language for me came as easily as breathing for 50 years, and I can't do it anymore," he told the New York Times in 2001. "The feeling is indescribable."

His debilitating final years brought him full circle. He was a sickly youth in his native Massachusetts, the well-read son of a working-class widow.

He idolized his father, a World War I Marine Corps veteran scarred by chemical warfare. He followed the family tradition by serving in the Marine Corps during World War II. He was a veteran of the Pacific theater and was almost mortally wounded in the Okinawa campaign.

Turning to a career in journalism and then book writing, Mr. Manchester was foremost fascinated by power -- its roots and its application. From his war experiences, he saw how power could devastate. As a foreign correspondent for the Baltimore Sun, he had a first-hand view of those making decisions affecting the life and well-being of nations.

Mr. Manchester combined a knowledge of the stresses of battle with his zestful eye for detail. His prose was simple and piercing, sparing nothing but illuminating the drama of ordinary events.

As a biographer, he chose as subjects the Rockefellers, the Krupp arms-making family, Douglas MacArthur and Churchill. His three works on John F. Kennedy -- whom the author met while both were recovering from war injuries -- brought him critical renown, financial security and best-seller status.

A frequent guest of the Kennedy family at Hyannis Port, Mass., Mr. Manchester won access to the president and his top advisers and used his insider status to chronicle the Camelot years and beyond. Some viewed him as too close to the family, writing adoringly of the president in his books "Portrait of a President: John F. Kennedy in Profile" (1962) and "One Brief Shining Moment" (1983).

He fetched more controversy with "The Death of a President: November 20-November 25, 1963" (1967), a meditation on the mourning of a nation. He said he had the "solemn responsibility" to offer a definitive account of the assassination.

Jacqueline Kennedy originally chose Mr. Manchester to write the book but soon tried to suppress its publication. Look magazine had made a record-setting bid of $665,000 for world serialization rights, and it was said that the former first lady thought so much money was unseemly for a project of that kind. She also had other concerns: the inclusion of some intimate family details and the political ramifications of publishing so close to an election year, 1968.

After much public debate about the integrity of all concerned, Mr. Manchester removed some passages. The book went on to sell more than 1 million copies and win praise for its masterful approach to dizzying current events.

Some reviewers found Mr. Manchester again guilty of hero worship. The author himself gave credence to that view in the 1985 introduction to the book's reprinting: "The Death of a President was not written for Jackie or any of the others. I wrote it for the one Kennedy I had known well and deeply loved, the splendid man who had been cruelly slain at 12:30 p.m. Texas time on Friday, November 22, 1963."

An exhaustive researcher and writer -- he once was hospitalized during work on the Kennedy assassination book -- Mr. Manchester spent years on his large projects and supported himself partly through magazine writing. He also taught at Wesleyan University, where he was a history professor emeritus.

After the Kennedy books, he returned to a previously disbanded project, "The Arms of Krupp, 1587-1968" (1968), a look at the Krupp steel and munitions family in Germany. The book explored the Krupp family's links to the Nazi regime, when the company's leader, Alfried Krupp, was convicted of war crimes at the Nuremburg trials but soon was released from prison because he was considered essential to the Cold War effort.

Mr. Manchester once wrote that his experience with "hard-corps Communists, Asian revolutionaries, agents of Arab intrigue and professional extremists in this country" never quite prepared him for work on the Krupp book. He found a network of former Nazis who trailed his every move and was harassed by police.

But he found the men in Krupp's history bizarrely fascinating, including one family member in the 19th century "who found the scent of horse manure so stimulating that he designed ventilator shafts to waft the fragrance from the stables through his study."

His next work, "The Glory and the Dream: A Narrative History of America, 1932-1972" (1974), plumbed the political, military and cultural events from the Depression to the Vietnam War, from Frank Sinatra to the Beatles. It was the era he knew best, and it garnered some of his best reviews.

He received a National Book Award nomination for "American Caesar: Douglas MacArthur, 1880-1964" (1978), a 793-page tour de force about what he called a "thundering paradox of a man."

With MacArthur, Mr. Manchester tackled one of the most controversial figures in American history. Revered by some as the iconic military man, detested by others for disobeying presidential directives, an egoist, a master strategist who tried to prevent casualties, a showboat, an undisputable leader and ultimately a tragic figure -- all seemed accurate descriptions of the general who helped inspire Americans during World War II.

"The personality and charisma of MacArthur are so successfully recreated in Manchester's biography that it is easy to forget that the book, unlike the man, had an author," the journalist Orville Schell wrote in Saturday Review. "This is to Manchester's credit. . . . [He] has written a thorough and spellbinding book. It is a dramatic chronicle of one of America's last epic heroes."

Mr. Manchester spent much of the past two decades working on his planned three-volume biography of Churchill. The first two books, "The Last Lion: Visions of Glory 1874-1932" (1983) and "The Last Lion: Alone 1932-1940" (1988), were bestsellers.

Although many critics focused on how unnecessary another Churchill project seemed -- Martin Gilbert's official Churchill biographies went to 9 million words, not to mention the political warrior's own autobiographies -- Mr. Manchester tapped new audiences through his gift for thrilling narrative.

Illness prevented Mr. Manchester from completing the third volume, which created great anguish among his followers. Paul Reid, a feature writer at the Palm Beach Post, was recently chosen to help finish the book.

"It's like asking a mother to let someone else raise her baby," Mr. Manchester said.

William Raymond Manchester was born in Attleboro, Mass., and raised in Springfield, Mass., after his father's death. A frail youth fond of poetry, he made friends with the toughest kid in the neighborhood to avoid being beaten up. It was an early exercise in power plays.

"Nobody else picked on me after that," he said.

He attended the University of Massachusetts and spent much of his time working odd jobs to complement his $60 annual scholarship money. He also was a varsity swimmer.

He served in the Marine Corps, attaining the rank of sergeant. He was shot in the kneecap on Okinawa's Sugar Loaf Hill but left the military hospital when he heard his regiment was moving on to Oruku peninsula. Wounded by mortar fire, he also was shot by a Japanese soldier near his heart. He was a recipient of the Purple Heart.

In his memoir, "Goodbye, Darkness" (1980), he found himself troubled by his repressed memories of war -- "You can't drown your troubles, your real troubles, because if they are real, they will swim," he wrote. Revisiting many of the scenes of action, he saw them disturbingly quiet, unremarkable places in peacetime. As he wrote, he struggled with his own motivations for fighting and surviving.

After the war, he graduated from the University of Massachusetts and received a master's degree in English from the University of Missouri. He wrote his master's thesis on H.L. Mencken, the acerbic Baltimore Sun columnist and author. The result was his first biography, "Disturber of the Peace" (1951), a well-received but largely flattering book.

"I fell in love with Mencken when I was an undergraduate," he told the Sun in 2002. "I had a professor that was highly critical of him, and I thought anyone capable of arousing this much wrath must be worth investigating."

With Mencken's help, Mr. Manchester began working at the Sun as a police reporter. Before leaving the paper in 1954, he had been given assignments in Europe and Asia, including some of the early conflicts between the French and the Vietnamese that soon become the Vietnam War.

He then spent two years as personal secretary to Mencken, whose strokes, like Mr. Manchester's own, left him incapacitated before his death in 1956. He read books to the dying author. "Much of Conrad and 'Huckleberry Finn' -- twice," he once said.

Mr. Manchester wrote four novels, and the best received of them was his first, "The City of Anger" (1953), a story he modeled on political corruption in Baltimore.

His wife, Julia Marshall Manchester, whom he had married in 1948, died in 1998. Survivors include three children; a brother; and three grandchildren.

William Manchester wrote about the Rockefellers, Douglas MacArthur, Winston Churchill and President John F. Kennedy.