Martin Luther King Jr. gestures during a speech at a Chicago Freedom Movement rally at Soldier Field, Chicago, July 10, 1966. ( Afro American Newspapers/Gado/Getty Images)
Jeanne Theoharis is distinguished professor of political science at Brooklyn College of CUNY and author of the award-winning "The Rebellious Life of Mrs. Rosa Parks." Theoharis and Brian Purnell are editors of the forthcoming book, "The Strange Careers of the Jim Crow North."

When he was 21, Martin Luther King Jr. and three of his friends stopped for drinks at a bar. It was June 12, 1950. The waitress refused to serve them. The four young people refused to leave. The bar owner threatened them, fired his gun in the air and forced them to leave.

But this wasn’t the Deep South. It was Maple Shade, N.J., and the state had recently passed an anti-discrimination law that King cited at the bar. With the help of the local NAACP, King and his friends filed a legal complaint with the police against the bar owner. But the complaint went nowhere when three white University of Pennsylvania students who witnessed the incident backed out and refused to testify about what had happened.

This was a pivotal lesson for King on the limits of Northern liberalism.

Throughout the 1960s, he tried to get people to see that racism was a national cancer, not a regional sickness. He called out Northerners who chastised the South while allowing racism to infect their own schools, workplaces and police departments. He objected to the myths and excuses tied to “culture,” “crime” “busing” and “law and order” that Northerners used to justify segregation, inequality and increased policing in their own cities. And he challenged the shock many white politicians, journalists and citizens expressed around the uprisings of the mid-1960s, insisting that the story began with the “winters of delay” — the long history of injustice and black protest that had been dismissed and disparaged for years preceding them.

As we memorialize King on the 50th anniversary of his assassination, we conveniently forget the King of the North. By “Southernizing” the civil rights leader, we keep his critiques at a safe remove. If we were to reckon with King’s criticisms of Northern complacency, it would become clear that the hypocrisy persists.

But we prefer an easier story of Northern good guys and Southern bad guys than one in which whites outside the South might have praised the Southern struggle but disparaged movements in their own home towns. We continue to find it easier to highlight problems in Southern hotspots like Charlottesville or Roy Moore’s Alabama than to address the inequities in Democratic Gov. Andrew M. Cuomo’s segregated and unequal schools in New York or Wisconsin’s devastating new voting restrictions. And we often hear calls for today’s activists to be more like Martin Luther King Jr., conveniently forgetting the threats and opposition that King confronted in all regions, not just the South.

In 1960, in a speech in New York City, King called for “a liberalism in the North that is truly liberal, that firmly believes in integration in its own community as well as in the Deep South.” (He used the term the “North” in its historical sense, born of the Civil War and the Great Migration, to mean everything outside the South.) King crisscrossed the country in the early 1960s, calling attention to the Southern struggle and calling out Northern injustice. He joined with movements across the country demanding the desegregation of housing and education, jobs, public assistance and an end to police brutality. As a result, he was repeatedly smeared as un-American.

King made multiple trips to Los Angeles, highlighting the city’s problems with segregation and police brutality well before the 1965 Watts uprising. In 1964, he joined the campaign against Proposition 14, a move by developers and citizens to block the state’s newly passed Rumford Fair Housing Act. He was labeled an extremist by many white Angelenos. They picketed with signs like: “King Has Hate, Does Travel” and “Thank God for [LAPD Police] Chief Parker” (who had come under fire from civil rights activists for police brutality).

In November, California “voted for ghettos,” as King put it, when Proposition 14, which nullified the Rumford fair housing law, passed by a two-to-one margin, even as Californians voted by similar margin to return Lyndon B. Johnson to the White House. The message was stark: Civil rights were noble — just not in California.

King fared no better in New York. In 1964, when the police killing of 15-year-old Jimmy Powell led to a six-day uprising in Harlem, King came to the city and called for a Civilian Complaint Review Board to provide public accountability over the police. City leaders basically ran him out of town.

A New York Times poll that year showed that a majority of New Yorkers felt the civil rights movement had gone too far. Motivated by their constituents, the Northern and Western sponsors of the 1964 Civil Rights Act secured a loophole in Title IV Section 401 to keep desegregation away from their schools without risking their federal funding.

King rejected the distinctions made by many Northerners that separated Southern segregation from their own. In April 1965, in a speech to the Massachusetts legislature, King pointedly explained that “segregation, whether it is the de jure segregation of certain sections of the South or de facto segregation of the North is a new form of slavery covered up with certain niceties.”

And so, two months after the Watts uprising, King took to the pages of the weekly magazine The Saturday Review to call out the feint of Northern innocence and the stubborn resistance to change there. King wrote of his growing disillusionment with Northern officials who “welcome me to their cities and showered praise on the heroism of Southern Negroes. Yet when the issues were joined concerning local conditions only the language was polite; the rejection was firm and unequivocal.”

Policing in particular concerned King. Issues of police brutality and surveillance knew no regional boundaries but often, as he pointed out, provoked different responses depending on region: “As the nation, Negro and white, trembled with outrage at police brutality in the South, police misconduct in the North was rationalized, tolerated, and usually denied.” He rejected the constant talk of black criminality by calling out white malfeasance from landlords to school officials to police and condemned the ways Northern whites blamed black people living in ghettos “for their own victimization.”

Over the next three years (which included a protracted open-housing struggle in Chicago, where city leaders initially agreed to more desegregated public housing and nondiscriminatory mortgages, only to renege with little national outrage), King increasingly zeroed in on the limits of Northern liberalism. “Negroes have proceeded from a premise that equality means what it says, and they have taken white America at their word when they talked of it as an objective. But most whites in America, including many of goodwill, proceed from a premise that equality is a loose expression for improvement. White America is not even psychologically organized to close the gap — essentially, it seeks only to make it less painful and less obvious but in most respects retain it.”

To the end of his life, Dr. King pointed out the lack of commitment to real desegregation in the North “[e]ven in areas where liberals have great influence — labor unions, schools, churches and politics.”

Grappling with the King of the North is to hear him speak to our present in uncomfortable ways. King called out the devastating power of “polite” racism and the blame-shifting that comfortably allowed many people — then and now — to justify these inequalities. He demonstrated the easy falseness of focusing on the South while expending little effort for real desegregation or police reform across the country.

White people didn’t like him for it, and disparaged him as an extremist in ways similar to how Black Lives Matter activists are critiqued today. And yet he continued to call on white Northerners, even many of his allies, to address the problems festering in their own back yard — problems Americans today would do well to address.