In those days, Oliver was a working-class African-American community with a thriving business district. Then, in April 1968, riots consumed the city after the death of Martin Luther King Jr. The arson and looting got so bad that National Guard troops marched up Oliver Street to restore calm.
The neighborhood never recovered. Crack cocaine moved in, then heroin. Residents who could, fled, leaving whole blocks abandoned. The "Hamsterdam" episode of "The Wire," in which police try to reduce crime by essentially legalizing the drug trade along certain streets of vacant homes, was shot there..
In 2002, an Oliver family with five children was burned to death in their home after the mother confronted local dealers. Money poured into the area, and a playground and children's center now memorialize the family. More recently, an alliance between a local ministers' group called BUILD and The Reinvestment Fund, a Baltimore nonprofit group that invests in distressed neighborhoods, has been working to build and rehab subsidized housing in the southeast corner of Oliver, near Johns Hopkins Medical Center and a planned biotech park.
Mr. Johnson, who grew up in a Baltimore suburb, had never really spent time in the city before moving there. "So I get to Baltimore as an adult, and I'm like: 'Who dropped the ball here?' "
He started beautifying the couple's little piece of Eden, planting trees and flowers and introducing himself to neighbors. He also met Dave Borinsky, who had invested in rehabbing his house. Mr. Borinsky was starting Come Home Baltimore, a for-profit development firm in the neighborhood, which was paired with a nonprofit foundation of the same name. The mission of the two organizations is to rehab vacant homes for sale, while helping current residents tap into assistance programs to fix up their own.