The modest brick rowhouse, painted white with black trim, is similar to the other handsome homes that line E Street on the eastern edge of Capitol Hill. Once it was a place of local political royalty, at the center of a neighborhood that symbolized African American ascendance in Washington, D.C.

Here, at 1236 E Street NE, is where Marion Barry resided when he was first elected mayor in 1978. Here is where Barry married wife Effi and hosted backyard parties for his neighbors, virtually all of whom were African American.

Knock on the door today and a white couple answer, the man in dress slacks and shirt as if he has just returned home from work. Behind the couple are two young children and a barking dog.

The evolution of Barry’s old block is the story of Washington’s transformation from a city that was overwhelmingly black to one in which blacks are barely a majority.

Few neighborhoods have been more at the center of that seismic shift than the streets surrounding the 1200 block of E Street NE, where newcomers and old-timers marvel at and grapple with their ever-changing landscape.

Long after Barry moved from the neighborhood in 1979, the blocks surrounding his old home were dominated by African Americans. As recently as 2000, the population was 84 percent black and 12 percent white, according to census statistics. But by 2010, there had been a dramatic retrenchment: Blacks made up 44 percent of the population, while whites accounted for 47 percent.

A shifting neighborhood

Vestiges of the old world are still visible: a faded and peeling Neighborhood Watch Area sign on the lamppost near Barry’s old place; rusted security bars over windows and doors; a shuttered shop at the corner of 13th and D streets.

But evidence of change — and greater affluence — is ubiquitous. The liquor store now sells imported beer. There are carefully tended forsythias and hyacinths blooming in the yards and Subarus and Mini Coopers parked on streets lined with freshly painted houses. A vacant lot once commandeered by vagrants and drug peddlers is now occupied by a condominium building.

The neighborhood’s newest amenity opened Friday at Kingsman Field: a dog park with a gravel, canine-friendly surface, poop-bag dispensers and red cans marked “pet waste.” Newly laid bricks are engraved with tributes to the likes of “Pepper and Senor Poopy Pants” and “Spike the Wonder Weimaraner.”

Three years ago, when she moved to the neighborhood from Arlington County, Kristen Thor, 33, said her friends said, “ ‘Oh my God, you’re moving to the ’hood!’ ”

“The area has really changed,” said Thor, a postural therapist who is white. “You see lots of young professionals, people with their kids. You didn’t see that when I first moved.”

Joanna Willis, 64, an African American nurse who has lived on E Street for 34 years, said she recognizes the neighborhood’s improvements. “The upkeep is better, there’s better trash service, street cleaning, police protection,” she said.

But she feels something is missing. The woman she knew as Mrs. Pernell occupied the house to her right, and Mrs. Pernell’s sister, Cora, lived in the house a couple of doors over on the left. Both are gone, she said, and she’s not sure who replaced them.

“At one time, the neighborhood was close-knit,” Willis said. “It’s not that way anymore.”

Others, however, say they have found community.

Ginny Madison, who is white and moved into a house a few blocks away five years ago, said police constantly raided the house across from hers. Now, she said, there are new residents and the raids have ceased.

“The creatures and the characters, as I call them, were always out,” she said as she dropped off her 3-year-old, Elle, at the Northeast Stars Montessori school on Maryland Avenue NE. “But two summers ago, I looked around and said, ‘Oh, it’s all of us walking around.’ ”

By “all of us,” she said she was referring to young professionals with children, most of whom she thinks are white. On occasion, she said, she has felt resentment from African Americans when she hears “under-the-breath comments, and how you’re addressed — like ‘Hey whitey.’ ”

“But I think it’s driven by socioeconomics,” Madison said. “It just so happens that the people coming in and making changes are a different race.”

Kionna Stephen, 39, an African American real estate agent who has lived on Emerald Street NE for 10 years, said she views the neighborhood’s racial evolution as a positive, particularly for her two young children. “It’s a diverse world we live in, and it exposes them to something other than themselves,” she said. “It’s good for everyone.”

Just over a mile east of Union Station, and south of bustling H Street NE, the neighborhood is defined by flat, quiet streets and adjoining brick rowhouses, many of them with matching conelike steeples. The neighborhood is in Ward 6, which went from a black majority to a white plurality over the past decade.

‘Good ’Ol Days’

Barry said he moved to the house on E Street in 1975, when he was a D.C. Council member and a leading advocate for black empowerment. Almost immediately, he said, a neighbor hosted a welcoming party for him. A few years later, he launched his candidacy for mayor a few blocks away, at an elementary School.

“We were a cohesive neighborhood,” Barry said. “People talked to each other. They were concerned about things in the neighborhood.”

After becoming mayor, he said, he moved away because he needed a larger home and could not afford to buy one on Capitol Hill. The couple who live in Barry’s former home declined to be interviewed without the consent of their landlord, who could not be reached. But they were aware, they said, that the house was once occupied by the former mayor.

Lacey Bigelow, 76, a retired African American carpenter who has lived around the corner from Barry’s former home since 1971, said that in those years he never saw white people in the neighborhood.

“Basically, here was black,” he said, standing outside his rowhouse on Emerald Street. Many of the people he once knew have moved away or died, he said. A year ago, he and his neighbors published a pamphlet called the “Emerald Street Good ’Ol Days,” in memory of some of those lost neighbors, including Chester and Charlene Hunter, both of whom lived across the street until they died.

“They lived on the sunny side of the street, so we’d be out here,” he said. “We had a shot or two.”

Bigelow doesn’t know who moved into the Hunters’ home, but he said he welcomes newcomers, white and black. “Most of them know my name. They say, ‘Hi, Mr. Bigelow,’ and I don’t even know who they are,” he said. “They give me respect, and I give them respect.”

Shop owners have tried to capi­tal­ize on the new arrivals.

On 15th Street, James Keo, the Cambodian-born owner of Viggy’s Liquor, said he changed the offerings when he bought the store in 2006, selling red and white wines and imported beers such as Peroni and Dos Equis. He also began selling convenience store items such as paper towels and snack food and thought about taking down the glass partition that separates him from his customers. A stabbing across the street made him reconsider.

What has surprised him, he said, is that the neighborhood’s new residents don’t mean bigger profits. In fact, he said, his earnings are down 40 percent.

“They’ve got money,” he lamented, “but they spend less.”

Furard Tate, the African American owner of a food services management company, lives in a rowhouse on 14th Street. He grew up three blocks away in a home his family has owned for more than 60 years.

He has witnessed the transformation and said he looks forward to the neighborhood’s future, even if it increasingly resembles the wealthy climes of Georgetown on the other side of the city.

“There won’t be as many African Americans,” he said, “but there will be myself and others who find importance in staying in their community.

“There are a lot of people stuck on hurt. I tell them, find the positive solution. Fix up the house or sell it or do something. Complaining is a waste of time.”

Staff writers Maggie Fazeli Fard, Dan Keating and Nikita Stewart and staff researchers Madonna Lebling and Magda Jean-Louis contributed to this report.