Joseph Reilly’s 45-year career in affordable housing began as a community organizer in New York City. As a 19-year-old, he worked to improve housing conditions and address other neighborhood issues that emerged in the Bronx.

“Organizing is about people,” he says. “Organizing is about communities working together to bring about positive changes and improvements in the quality of life. It was all about trying to make sure people were treated fairly and had a safe, secure place to live.”

This early work became a foundational experience that helped guide the rest of Reilly’s career, which has included positions at the New York City Department of Housing Preservation and Development and JPMorgan Chase, where he was national manager for community development real estate.

Each role was pivotal, preparing him to lead The Community Development Trust (CDT), where he has been president and CEO since 2007. Celebrating its 25th year, CDT is a provider of long-term capital for the preservation of affordable housing.

Under his leadership, the organization has amassed an equity investment portfolio of more than 22,000 units and a debt portfolio of 16,000 units, totaling more than $3.6 billion in value. The organization, a Community Development Financial Institution, has also financed six charter schools. In all, the properties serve about 140,000 people across the country.

Earlier this year, CDT, along with The Michaels Organization and Goldman Sachs Urban Investment Group, purchased 90 affordable housing communities to preserve more than 10,000 affordable apartments. The $1.2 billion acquisition was CDT’s largest to date.

Reilly has never considered a business decision without making sure the needs of residents came first, according to Andrew Ditton, chairman of CDT’s board and a former managing director at Citigroup.

“CDT was created not just to produce housing but to keep it affordable for as long as possible,” he says. “Joe believes deeply in that mission and never advocates for a project that has only short-term affordability prospects.”

Few mission organizations have walked the walk like CDT and continued to grow, according to Ditton, who calls Reilly one of the unsung heroes in the affordable housing space.

Perhaps, it’s because his days as a community organizer have never really left him.

“As I look back on 45 years in this field, I’ve been fortunate to have had great opportunities—working for a nonprofit in the Bronx, working for New York City government, working for one of the largest financial institutions in the world,” Reilly says. “The work we do at CDT allows me to use all of those previous experiences to help bring about positive change in people’s lives today. I’ve been very fortunate to have this opportunity, which allows me to use all of the skills that I’ve accumulated over my entire career.”