Dr. Martin Luther King Jr. speaks in Memphis in March 1968 during the sanitation workers’ strike. A garbage can is being passed through the crowd to collect donations in support of the striking workers. | University of Mississippi Libraries

Today, April 4, the 49th anniversary of the assassination of Dr. Martin Luther King, thousands will join Fight for $15 and the Movement for Black Lives to march in Memphis and in cities across the country in the fight for decent pay and racial justice.

These demonstrations are more than a fitting tribute to Dr. King; they are taking up his unfinished agenda. Dr. King saw the Civil Rights Movement as a symphony with many movements: First came the victory that ended apartheid in America. Then came the victory to guarantee voting rights. In his last days, Dr. King was working feverishly on the third movement, the movement for economic justice, organizing a Poor People’s Campaign that would bring together people from across lines of race, religion, and region to demand economic justice.

King understood that what he called the “giant triplets of racism, extreme materialism, and militarism” had to be challenged to make America better.

In the midst of this, Dr. King came to Memphis, summoned by the courage and sacrifice of black sanitation workers striking for decent pay, job safety, respect, and a union. They protested both the racial discrimination they faced on the job and the absence of decent wages and conditions. They demanded a union so that they could stand together and bargain collectively.

Dr. King responded to their call because he preached in his last speech that we need to develop a “dangerous unselfishness.” The question, he said, is not, “If I stop to help this man in need, what will happen to me?” The question is, “If I do not stop to help the sanitation workers, what will happen to them?”

Now, 49 years later, people are stirring once more. Fight for $15 began five years ago when fast food workers in New York City went on strike demanding a $15 per hour minimum wage and a union. They were dismissed as “unrealistic,” even by Democrats. But the movement spread across the country, and now more than 22 million Americans have benefited from an increase in minimum wages, and some 10 million on are on a path toward $15 an hour as city ordinances step up wages. A $15 minimum wage is written into the Democratic Party platform, and it is being written into law in more and more cities across the country.

The Movement for Black Lives arose in protest against our criminal injustice system, in which blacks suffer both mass incarceration and too often violence from those who are supposed to protect them. In stunning nonviolent protests across the country, the movement has propelled the cause of reforming the police and discriminatory sentencing practices.

In the last address of his life in Memphis, Dr. King noted that he was happy that the Almighty had allowed him to live in the second half of the 20th century. “Now that’s a strange statement to make,” he told those gathered, “because the world is all messed up. … Trouble is in the land. Confusion all around. … But I know, somehow, that only when it is dark enough can you see the stars.”

Dr. King was excited because people were on the move, a revolution in human values was beginning. He knew the road was long and hard. He knew there would be setbacks and reverses. But he believed that if “we will but make the right choice, we will be able to speed up the day, all over America…when justice will roll down like waters and righteousness like a mighty stream.”

Today, this is a troubled nation. Inequality has reached obscene extremes. Economic and racial injustice still blights lives and stamps out hope. Yet today thousands of people are making the “right choice,” and are on the move, sacrificing to make America a better nation. Surely Dr. King smiles down upon them.