Had Martin Luther King, Jr. not been killed as he stood on the Lorraine Motel’s second-floor balcony on that spring evening in 1968, it’s almost certain that the Baptist preacher would have remained a powerful voice against injustice. While King would have spoken out against racism in the ensuing years, it’s important to remember that the 1964 Nobel Peace Prize winner had begun to pivot his activism to economic inequality and antiwar causes by the time of his death, says Stanford historian Clayborne Carson, who also serves as director of the university’s Martin Luther King Jr. Research and Education Institute. It was economic inequality and fair housing that led him to march through a rainstorm of bottles and bricks in Chicago in 1966 and drew him to Memphis in support of striking sanitation workers.

“I don’t think of him primarily as a civil rights leader during the last years of his life,” Carson tells HISTORY. “Once the Voting Rights Act passed in 1965, his goals extended beyond civil rights at that point. In his Nobel Prize lecture he pointed out the triple evils in the world. Racial oppression was one, but poverty and war were the other two, and those were what he had turned his attention to.”

“The entrenched racism King confronted during his trip to Chicago in 1966 and the escalation of the Vietnam War broadened his understanding of civil rights to include the entire national landscape and the nation’s role abroad,” says Lillie Edwards, professor emerita of history and African-American studies at Drew University. “By 1968, this broader landscape signaled that he was fully engaged in keeping pace with new arenas of social justice and willing to embrace new paradigms and new strategies.”

High on King’s list of plans was the Poor People’s Campaign, which he had announced in November 1967 along with other civil rights leaders. He planned for an initial group of 2,000 impoverished Americans of all races to descend upon Washington, D.C., in May 1968 to lobby for an “economic bill of rights” that included jobs, unemployment insurance, a fair minimum wage and more low-income housing.

Before they could march into the nation’s capital, however, King’s followers found themselves marching behind a a mule-drawn wagon bearing his casket through the streets of Atlanta. The Poor People’s Campaign went on as scheduled, but it floundered without King’s leadership. The “economic bill of rights” never came to fruition.

Edwards says King’s presence would have boosted the profile of subsequent anti-poverty campaigns. “Supporting garbage workers in Memphis signals to us that King would have been a hands-on participant in movements to empower the poor and working class. His presence would have provided additional gravitas, leverage and media attention to local movements that the media and general population might have ignored,” she says.

Had King lived, he likely would have continued to speak out against U.S. involvement in the Vietnam War. Exactly one year before his death, King delivered one of the most controversial speeches of his life inside Manhattan’s Riverside Church in which he called the U.S. government “the greatest purveyor of violence in the world today” and said it was morally indefensible to send African-American troops to “guarantee liberties in Southeast Asia which they had not found in southwest Georgia and East Harlem.”

While some argue that racial relations would have been different had King lived, Carson says that expectations that King could have dramatically altered the ensuing direction of the civil rights movement, “economic bill of rights” and Vietnam War discount the power of the turning tide of the country. “The United States is like an ocean liner. One person is not going to change its momentum and direction. Even a great individual would not be able to turn it around and make it go in a different direction. The basic attitudes of people don’t change rapidly, and the nation was heading in a much more conservative direction after the 1964 election. We entered an era in which it was difficult enough to defend the gains that had been made before.”

In the year before King’s death, peace advocates tried to draft him to join a third-party antiwar ticket to run with pediatrician Benjamin Spock in the 1968 presidential election. King ultimately decided against a try for political office, and Carson doesn’t believe that he would ever have done so in the future, unlike civil rights leaders such as Andrew Young and Jesse Jackson who were at King’s side when he died. “He made a decision that he was not going to be a candidate for office,” Carson says. “He would continue to be a voice in the political arena but as a private citizen.”

Ironically, there may never have been a federal holiday honoring King had he not been killed so suddenly in 1968. King was not a universally revered figure at the time of his assassination. In the five years leading up to his death, King appeared on the top 10 of Gallup’s most-admired list only twice—in 1964 and 1965. In 1967 Alabama’s segregationist governor, George Wallace, ranked eighth on the list, while King could not crack the top 10. Gallup reported that nearly twice as many Americans in 1966 had a negative view of King as a positive one—and that was even prior to his controversial Riverside Church speech. By 1999, however, a Gallup poll found that King ranked behind only Mother Teresa as the century’s most-admired person.

Edward says public memory of King would have been quite different had he lived. “King is a martyr whose nobility of consciousness—non-violence—is embedded in the American and international consciousness,” she says. “However, King’s martyrdom has also diluted, if not erased, the power of his militant and revolutionary messages about human dignity and taking immediate rather than piecemeal action. Some people find it easy to embrace what I call ‘the birthday King’ who is devoid of urgency and militancy. The public has framed a ‘moderate’ King as a foil to a ‘militant’ Malcolm X for this reason.”

Death brought King a reverence that never existed during his life, and in 1983 the federal government designated his birthday as an annual holiday. “If he had lived, there clearly wouldn’t be a Martin Luther King holiday,” Carson says. “I think it was easier to see the idea of the holiday when he was no longer around.”