Martin Luther King Jr. remains frozen in time for many Americans. Seared into our consciousness is the man who battled Southern segregation.

We see him standing before hundreds of thousands of followers in the nation’s capital in 1963, proclaiming his dream for racial harmony. We see him marching, arms locked with fellow protesters, through the battleground of Alabama in 1965.

But on the 50th anniversary of his death, it is worth noting how his message and his priorities had evolved by the time he was shot on that balcony at the Lorraine Motel in Memphis in 1968. Dr. King was confronting many challenges that remain with us today.

He was battling racism in the North then, not just in the South. He was pushing the government to address poverty, income inequality, structural racism and segregation in cities like Boston and Chicago. He was also calling for an end to a war that was draining the national treasury of funds needed to finance a progressive domestic agenda.

This may not be the Dr. King that many remember. Yet, his words resonate powerfully – and, perhaps, uncomfortably – today in a country that remains deeply divided on issues of race and class.

“All the issues that he raised toward the end of his life are as contemporary now as they were then,” said Taylor Branch, the Pulitzer-Prize winning historian who has written several books about Dr. King.

It is no surprise that Americans remember the man who focused on demolishing the legal underpinnings of Jim Crow.

Holding on to the memory of the earlier Dr. King allows us to focus on our nation’s progress, not on the deeply entrenched problems that remain.

“Policy makers of the white society have caused the darkness; they created discrimination; they structured slums; and they perpetuate unemployment, ignorance and poverty,” Dr. King said in 1967, referring to bias in zoning, public budgets and employment.

His marches into northern white neighborhoods touched off a backlash among white leaders and residents who had supported similar tactics in the south. His popularity plummeted.

His call for an interracial coalition to demand “jobs or income now” was greeted skeptically by some of his supporters and by members of the Black Power movement.

His call for an end to the Vietnam War outraged President Lyndon Johnson, lawmakers and others. Even some of his aides doubted the wisdom of that decision and his plan to mobilize a poor people’s campaign.

“He was far more visionary than those around him,” said Clayborne Carson, the director of the Martin Luther King, Jr., Research and Education Institute at Stanford University.

What would Dr. King make of America today?

Historians believe he would marvel at the expansion of rights for women and the L.G.B.T.Q. community, the growth of the black middle class and the number of black elected leaders, including America’s first black president.

He would also see a country beset by many of the problems he had urged Americans to focus on during the last years of his life.

“I think we should have listened to him then,” Mr. Branch said. “We really ought to listen to him now.”

— Rachel L. Swarns