March 31, 1968 -- one of those unforgettable days as it turned out -- began at 7 a.m. Lyndon Johnson had spent a restless night.

Lady Bird recalls: "His face was sagging and there was such pain in his eyes as I had not seen since his mother died. But he didn't have time for grief. Today was a crescendo of a day. At 9 in the evening, Lyndon was to make his talk to the nation about the war. The speech was not yet firm. There were still revisions to be made and people to see."

The war in Vietnam had shattered Johnson's presidency, overshadowing his considerable achievements in the war on poverty, civil rights, education, medical care and a whole range of domestic programs. The streets were now filled with antiwar, anti-LBJ taunts and protests.

Inside the White House, the Johnsons could hear the chants: "Hey, hey, LBJ, how many babies did you kill today?"

The tide of antiwar feeling dated back to early 1966, reaching a point where in an ad-lib during a speech to a Democratic Party dinner in Chicago, Johnson referred to those who did not like the war as "nervous nellies." It was a phrase that was to haunt him for the rest of his presidency.

Nothing seemed to work. There was pacification, Vietnamization, "hearts and minds" galore -- and hundreds of thousands of U.S. fighting men backed up by hundreds of millions of dollars worth of the latest and deadliest equipment.

Obviously, Vietnam was never far from the president's mind in 1967 and every new move by him drew more fire from the increasing ranks of the peace bloc. A particularly bitter storm erupted in the year when he ordered new air strikes on Hanoi.

There were on-again, off-again attempts -- how serious depends on the speaker and the timing -- to get the participants to sit down, anywhere in the world and almost under any circumstances, to negotiate.

But it took Tet, the Vietcong offensive in January 1968, to bring home once and for all the terrible quality of the war. The shock of pictures showing Vietcong damage to the U.S. Embassy in downtown Saigon, and the sight of American soldiers dead inside its walls, stunned Americans.

Lyndon Johnson was in deep, deep trouble and he knew it.

So did others. Robert F. Kennedy, who still saw himself as the guardian of the keys to Camelot, announced his candidacy for the Democratic presidential nomination.

Just before 9 p.m. on March 31, 1968, millions of persons across the country flicked on their television sets to hear Lyndon Johnson. Seated at his desk, flanked by flags of his country and his office, he began:

"Tonight, I want to speak to you of peace in Vietnam and southeast Asia."

First, he reviewed the outcome of the Tet offensive, saying that the communists had failed to collapse the Siagon government or its army. Then he renewed his offer to stop the bombing of North Vietnam and asked for immediate peace talks.

Then Johnson appealed for national unity and added:

"With America's sons in the fields faraway, with America's future under challenge right here at home, with our hopes and the world's hopes for peace in the balance every day, I do not believe that I should devote an hour or a day of my time to my personal partisan causes or to any duties other than the awesome duties of this office -- the presidency of your country.

"Accordingly, I shall not seek, and I shall not accept the nomination of my party, for another term as your president."

Robert Fleming, a deputy press secretary: "When he finished saying he wouldn't run again, and the cameras went off, Mrs. Johnson and the two girls were sitting there, and one of the girls was crying, the other was smiling. They stood up, he stood up, and Mrs. Johnson went over and threw her arms around him and said, 'Nobly done, darling.'"

Horace Busby, a Johnson friend and adviser: "I don't think there were any regrets later. That is the invention of the so-called psychohistorians. Nor any bitterness. Nor any feeling -- well, of course, you always have moments, everybody does, of regret over something as major as that."

Hubert II Humphrey heard the speech on radio in Mexico City, where he and Muriel were visiting. He wept, but behind the tears was the realization that it meant he had the best chance now to grab the brass ring that so often had eluded him in the past.

Four days later, another trauma gripped Americans. Martin Luther King Jr. was assassinated in Memphis. The news touched off the greatest wave of violence in the history of the civil rights movement. By the time Johnson appeared on television, about two hours later, to express his and the nation's grief, rioting and looting had broken out in cities all over the country.

Twenty-three days later, on April 27, another trauma, this one even more dramatic because it happened on television, made the United States seem a symbol of violence and madness. Robert F. Kennedy was shot and fatally wounded in the kitchen of a Los Angeles hotel.

The nightmare of dissension and street violence that was the 1968 Democratic National Convention in Chicago ended, to no one's surprise, with the nomination of Humphrey. Nor was Richard M. Nixon's election in November all that surprising, given the national mood of rejection and hatred for the man -- and the administration -- that Americans held responsibile for the war.

So January was, it sometimes seemed, one continuous farewell party for Johnson. He was going out in style. But there were a few remaining ceremonial obligations. The State of the Union message, for one.

Johnson delivered it in a soft, never abrasive tone of voice, and when he finished, no one for a moment seemed to realize it was over. When they did, cheers came from both Republicans and Democrats. As he walked back down the aisle, dozens of hands grabbed for his. Many members of Congress were misty-eyed.

Then it was back home -- to the ranch on the banks of the Pedernales, in the Texas hill country where Lyndon felt most comfortable.

To no one's surprise, the retirement did not begin well. But soon LBJ settled down to a new, offstage pattern of living. He traveled, often on sentimental trips, worked on his political autobiography, oversaw the transfer of his papers to the new Lyndon Baines Johnson Library at the University of Texas. That library and the establishment of the Lyndon Baines Johnson School of Public Affairs at the school were Johnson's hope for posterity.

In March 1970, Johnson was hospitalized with angina, and was never without pain again. Then, in the spring of 1972, he and Lady Bird were visiting Lynda and her family in Charlottesville, Va., when Lyndon suffered another heart attack.

Leo Janos, a member of Johnson's presidential staff: "Convinced he was dying, he browbeat Lady Bird and his doctors into allowing him to fly home to Texas. So, late in the night of his third day of intensive care, a desperately sick LBJ was rushed to the airport and ferried back to Brooke Army Medical Center in San Antonio. The departure was so sudden that the Charlottesville hospital director, hearing a rumor that Johnson might try to leave, rushed to the hospital only to find LBJ's empty wheelchair in the parking lot."

He survived, but the remaining seven months of his life became a sad and pain-wracked ordeal. A portable oxygen tank stood next to his bed and Johnson periodically interrupted what he was doing to lie down and put on the mask to gulp air.

Shortly after the dedication of the library, it was decided, largely by Johnson himself, to conduct a series of conferences devoted to various public issues. Johnson attended the first, on education, and began immediately to plan a second, scheduled Dec. 11, 1972, on civil rights.

Hugh Sidey of Time magazine: "The men and women who carried the civil rights banner for two decades had assembled. There were some new faces among them, but the focus was on men like Hubert Humphrey, Roy Wilkins, Clarence Mitchell and former chief justice Earl Warren. They showed up with more wrinkles than they used to have, more gray hair, and lot more discouragement. From the beginnings of the two-day meeting, it was plain that civil rights no longer had a clear national leader."

At one point, as Johnson prepared to speak, he took a nitroglycerin pill out of his pocket and popped it into his mouth, the first time, and the last, that he did that in public. He talked in a low but steady voice for about 20 minutes:

"We cannot obscure this blunt fact, the black problem remains what it has always been, the simple problem of being black in a white society. That is the problem which our efforts have not addressed.

"To be black, I believe, to one who is black or brown, is to be proud, is to be worthy, is to be honorable. But to be black in a white society is not to stand on level and equal ground. While the races may stand side by side, whites stand on history's mountains and blacks stand in history's hollow. We must overcome unequal history before we overcome unequal opportunity.

"This is precisely the work which we must continue. This is the whole important part of this meeting. Not what we have done, what we can do. So little have we done. So much we must do."

Sidey: "As he finished, people pressed forward, all reaching for a bit of the old magic. But nobody got so much of it as Mr. Youngblood, a thin, aging black who used to wait on tables in Austin's ancient Driskill Hotel, where Johnson sweated out election night returns. The former president and the former waiter stood there for a few seconds gripping hands, and if any questions lingered about what Lyndon Johnson had tried to do for his country, they were answered right then."

That was mid-December. Lyndon Baines Johnson died at 3:50 p.m. on Jan. 22, 1973.

A few minutes before his death he called the ranch switchboard from his bedroom, and two Secret Service agents rushed there with a portable oxygen unit. Lyndon was lying on the bed. They tried to revive him, but he was gone. Lady Bird was away; his daughters absent.

Haynes Johnson, of The Washington Post: "Perhaps the most poignant aspect of Lyndon Johnson's death is that this most public man, who was in his element when surrounded by cheering crowds, died along, calling for help."