Dorchester lost one of its most generous and loyal sons this week. Robert L. Marr died on Monday after a brief illness. He was 86.

Bob was the son of Colonel Daniel Marr, the namesake of the original Boys and Girls Club, which opened on Deer Street in 1974. The Marr brothers— Bob and Dan Jr.— raised the money and drove the project— leaning on their impressive network of friends and business contacts associated with the Marr Companies and the New England Patriots.

The fifth-generation construction company— which Bob’s grandfather, Daniel F. Marr, founded in 1898— specializes in steel erection, scaffolding, and cranes. They helped build large parts of the city of Boston as we know it from their headquarters on Dorchester Avenue, just north of Andrew Square in South Boston.

Their equipment and employees were pivotal to the construction of Hynes Auditorium, the Museum of Science, the Back Bay Hilton and Westin Copley hotels, International Place and Rowes Wharf. Closer to home, they were instrumental in building Carney Hospital, the JFK Library, and even the landmark Rainbow Gas Tank.

Bob Marr was also a key player in the history of the New England Patriots. His father was a co-founder and Bob served as the team’s president in 1974-75.

But it’s the family’s involvement in the Boys and Girls Clubs and the neighborhood’s Catholic schools that has left the most indelible and important imprint on Dorchester. Bob Marr has been a constant throughout the decades, showing up as a board member and frequent presence at the club’s facilities.

“My father, for whom the club is named, grew up nearby and so did my brother and I,” Bob Marr told the Reporter in 2015. He was in the club’s gym that day to personally congratulate scores of young people, all beneficiaries of thousands of dollars in scholarship money to attend Catholic schools in the Archdiocese of Boston.

“We are so pleased that my brother [Dan’s] gift both helps to grant young people in Dorchester the educational opportunity to create better lives, and continues a proud legacy in the Marr family tradition.”

The scholarship fund, set up first by Bob’s late brother, Daniel F. Marr, Jr., has given out well over $1 million and counting since 1992, a blessing not only to the beneficiary families, but also to the school system locally.

It’s impossible to calculate how many lives Bob and his clan have changed for the better through the clubhouse on Deer Street that still bears his father’s name, said Bob Scannell, who has run the club since 1987, on Tuesday.

“Back in the day, Bob Marr really carried this organization on his back, and over 50 years he never stopped,” said Scannell. “Bob didn’t just write checks and walk away. He was involved in every committee, every event. And look at the legacy he leaves behind.”

Contemplating a Dorchester without the Marr clubhouse and the Boys and Girls Clubs of Dorchester is unnerving, particularly for those of us who’ve seen how waves of city kids— many of them without stable and supportive homes— have thrived and succeeded because this facility and the people who run it refused to let them fail.

Bob Marr and his family made that possible.

Bob Marr's wake will be held on Tues., Aug. 16 from 4-8 p.m. at St. Agatha's Church in Milton. His funeral Mass will be celebrated on Wed., Aug. 17 at 10:30 a.m., also at St. Agatha's Church.