Almost a decade ago, reporter Jonathan Tilove was in the Mississippi Delta, working on a story about the Freedom Summer’s 30th anniversary. As he traveled, he noticed that many of the towns on his itinerary had renamed a street for the Rev. Martin Luther King Jr. Tilove knew there were many such memorials to the slain civil-rights leader, but he had never given much thought to the phenomenon. He wondered, half seriously, whether it was possible to travel across the country from one MLK thoroughfare to another.

The idea was quickly buried by more pressing stories on Tilove’s beat, covering race for the Newhouse newspaper chain. But between 1999 and 2001, he returned to the project, visiting nearly a dozen communities with streets named for Martin Luther King, staying a week or so in each to hang out with locals. Tilove, now 49, turned this reporting into a six-part newspaper series that ran in 2002, then expanded the project into Along Martin Luther King: Travels on Black America’s Main Street.

For the book, Tilove—a resident of D.C.’s Glover Park neighborhood—went to major metropolitan areas including Atlanta, New York, and Chicago, as well as to smaller Southern civil-rights battlegrounds such as Jackson, Miss., and Selma, Ala. He visited Oakland, Calif., home of the Black Panthers, as well as the predominantly white city of Portland, Ore. His travels took him to the Texas towns where a black man was dragged to his death from the back of a truck and where African-Americans first celebrated Juneteenth, the holiday that marks the liberation of slaves in the Confederacy.

He discovered a web of King streets that “connects a community nationally but was created organically.” And everywhere he went, Tilove asked people about King’s legacy—and how well the streets named in his honor reflect his principles.

It was no softball question. In the public imagination—predominantly among whites, but to a certain extent among blacks, too—streets named for King have become closely linked with urban decay, poverty, and crime. And though Tilove found that many King-street neighbors understand and regret this popular association, he also found that the King streets serve as a genuine source of pride. Plenty of these boulevards are studded with fast-food outlets and vacant lots, but many also serve to anchor traditional commercial and residential hubs for the cities’ African-American communities.

“Even a lot of the people who say it’s a shame still take a certain pride that they created the space,” Tilove says.

One of Tilove’s discoveries was that the MLK-street phenomenon had emerged piecemeal over time. He found no act of Congress urging the changes, no foundation handing out seed money, and no high-profile political leader making the project a cause célèbre. Rather, the street names materialized following the application of local pressure in, at last count, 700 American communities.

To be sure, the idea hasn’t been controversy-free. Angry voters in Harrisburg, Pa., and San Diego rescinded their MLK designations in the ’80s, and residents in other cities have either blocked implementation of MLK street names or steered their placement away from white areas. Pure bigotry? Yes, in many cases. But in others, the prejudice took less obvious forms: for instance, business owners fearing that white customers wouldn’t shop at stores with an MLK address. Indeed, commuter highways have become popular name-change prospects, because renaming them for King doesn’t require address changes for either residents or businesses.

If this reality is distressing for Americans who deplore racism, Tilove nonetheless found reason for optimism. “King has become a generally celebrated figure, and the price you pay for that is the risk of losing your meaning and your edge,” Tilove says. “But the fact is that people have had to struggle to create these streets, and all that ferment brings his memory back in ways that other memorials don’t….I can’t imagine any better living testament.” —Louis Jacobson