Through the months preceding his assassination on April 4, 1968, the Rev. Martin Luther King Jr. was haunted by a sense of impending death. He shared that premonition with his aide Andrew Young, who was with King when a fatal bullet struck, 50 years ago.

"He talked about death all the time," Young told Tavis Smiley, author of "Death of A King."

For his 2014 book, Smiley asked those who had marched alongside King what they recalled of his mood in 1968. The comedian and activist Dick Gregory reported that King, with tears in his eyes, said he was certain to be killed.

King had faced death threats since the 1950s, when he emerged as the acknowledged leader of the civil-rights movement. But in 1968, the threats reached a crescendo.

The Chicago Tribune saw it the other way around: King was the danger. The paper was verbally at war with King because of his open-housing campaign in Chicago two years earlier.

Five days before his murder, the Tribune observed in an editorial: "We think the time has arrived when the country must ask itself how much more it is going to put up with from this incendiarist."

The FBI took the threats seriously, though its director, J. Edgar Hoover, and King had traded insults. When King attended a meeting of black pastors in Miami in February 1968, the FBI received a bomb threat, so armed guards were stationed outside King's room. Miami police insisted King stay out of sight during the five-day conference.

In March, the announcement that King would address the Human Relations Council of Grosse Pointe, Mich., an affluent Detroit suburb, produced a rash of threats. To protect King, the police chief sat on his lap in the car carrying King to the high school where he spoke.

Might such incidents have set King to worrying that he wouldn't live to see the results of the antipoverty campaign he was struggling to organize?

On March 3, he preached a sermon titled "Unfulfilled Dreams" at the Ebenezer Baptist Church in Atlanta, which he pastored. Referencing the Old Testament, and noting that King David hadn't seen his dream of a Jerusalem temple realized, he preached: "Life is a continual story of shattered dreams."

King's "Unfulfilled Dreams" sermon was a callback to his 1963 March on Washington, where he had delivered his iconic "I Have a Dream" speech that inspired legislation aimed at Jim Crow, the systematic discrimination suffered by blacks in the South. But having concluded that political equality was meaningless without a measure of economic equality, on Dec. 4, 1967, King announced he would lead a new march on Washington in the spring of the following year.

Demonstrators for the "Poor People's Campaign" would set up a tenant farmer's shack in front of one of the buildings of the Smithsonian Institution, a group of museums commemorating America's achievements.

"We will go there, we will demand to be heard, and we will stay until America responds," King proclaimed. "If it means jail, we accept it willingly, for the millions of poor already are imprisoned by exploitation and discrimination."

Those words drew a firestorm of opposition, even from King's loyal supporters. Bayard Rustin, who organized the earlier march, was opposed to a new one. So, too, was Jesse Jackson, another rising civil-rights leader in King's circle.

King's critics must have been on his mind on Feb. 4, 1968, when he delivered a sermon at Ebenezer Baptist. It was a riff on a biblical story about "an itinerant preacher," as King put it, "who just went around serving and doing good."

But when that preacher was 33, "the tide of public opinion turned against him," King noted. "His friends turned him over to [his enemies], and while he was dying the people who killed him gambled for his clothing."

King's opponents saw his proposed march as an invitation to rioting. In the 1960s, one inner city after another had exploded in deadly and destructive riots. King explained the violence with a metaphor: "A riot is the language of the unheard."

The Chicago Tribune rejected that argument in a Jan. 21, 1968, editorial: "Every time there is a riot in the streets you can count on a flock of sociologists rushing forward to excuse the rioters." King's "nonviolence," the Chicago newspaper added, "is designed to goad others into violence."

Simultaneously, King was under attack by a younger generation of black militants who rejected his pacifist philosophy as weak. Their conclusion was echoed by Adam Clayton Powell Jr. "I don't call for violence or riots, but the day of Martin Luther King has come to an end," said Powell, a longtime U.S. congressman from New York.

King attracted still more enemies as an opponent of the Vietnam War. Hecklers trailed him, shouting: "Traitor!" "Commie!"

All the while, he was being implored to come to Memphis, where the city's sanitation workers had gone on strike on Feb. 12. The mayor refused to recognize their union, and demonstrators were gassed.

King was exhausted. His days were a blur of listening to the personal stories of poverty from across the South — one mother said her children couldn't go to school because they had no shoes — and rushing off to big-city fundraisers, so his staff could be paid.

But by March 17, he couldn't deny the strikers' pleas and said he'd be there. The next day, his mood was lifted by the crowd of 25,000 that greeted him in Memphis' Mason Temple.

"You are reminding not only Memphis but this nation that it is a crime for people to live in this nation and receive starvation wages," he told them. "What does it profit a man to be able to eat at an integrated lunch counter if he doesn't have enough money to buy a hamburger?"

But when he returned on March 28, to lead a march, it was a disaster. Looters broke shop windows. The police responded with tear gas and nightsticks, and King fled the chaotic scene.

The Chicago Tribune gleefully noted in its March 30 editorial, "King took it on the lam, sprinting down a side street and making off in a jalopy."

The New York Times urged King to cancel his Poor People's Campaign.

Yet King would not be dissuaded. Three days after the failed march, he delivered a sermon in Washington's National Cathedral, in which he wrestled with his options.

"Cowardice asks the question — is it safe?" he noted. "Conscience asks the question — is it right?"

He returned to Memphis on April 3, only to be served with a court order banning his planned demonstration. His flight had been delayed by a bomb scare, and there was a torrential downpour. Bone-tired and thinking few would show up at a scheduled rally, he asked his good friend Ralph Abernathy to sub for him.

Shortly, Abernathy phoned King at their motel. The crowd was not about to leave until they heard King. So he hurried over and spoke about his reaction to the latest threat.

"But I'm not concerned about that now," he said. "I just want to do God's will. And he's allowed me to go to the mountain. And I've looked over, and I've seen the promised land. I may not get there with you. But I want you to know tonight that we, as a people, will get to the promised land."

The next day, as his lawyers prepared for a court fight, King took it easy at the Lorraine Motel. About 6 p.m. he stepped out on a balcony. From a nearby rooming house, James Earl Ray, an escaped convict, fired a single shot.

"We always knew this could happen," said Coretta Scott King after she was told her husband was dead.

Five days later, enormous crowds lined the route of King's funeral procession through the streets of Atlanta.

Famous names were among the mourners — professional athletes, celebrated entertainers, senators, governors and presidential candidates. It was an election year. But the procession also bore witness to the struggles of the little people for whom King fought.

His casket was carried on a farm cart pulled by two mules.