Robert Hohler, longtime champion for social justice, 78

“If you asked him to talk about it, he would, but it wasn’t what he led with,’’ said David Wertheimer a deputy director with the Bill and Melinda Gates Foundation, who considered Mr. Hohler a mentor in philanthropy. “He led with his passion that ending homelessness was not only morally the right thing to do, but economically the right thing to do.’’

Mr. Hohler, 78, who was a leader of OxFam America in the 1970s and a firebrand of the antiwar and civil rights movements in the 1960s, died June 2 of a heart attack while hiking with his wife, Karen, on vacation in England. They were on a walking tour of Hadrian’s Wall in the village of Heddon-on-the-Wall near Throckley, Northumberland, when he collapsed.

He started at the Melville Trust at its inception in 1991 and was a key leader in Melville’s work over the last five years to stabilize a housing and business development in Hartford. Known as Billings Forge, the mixed-income 98-unit development has job training programs, a farmer’s market, and a farm-to-table restaurant called Firebox.

Mayor Pedro E. Segarra said Hartford “is sad beyond measure’’ at the news of Mr. Hohler’s death. Billings Forge, he said, was “a testament to his mission of individual empowerment and sustainable communities.’’

Mr. Hohler’s devotion to philanthropy was recognized in 2009 when he received a premier award from the Council on Foundations, a nonprofit association of more than 2,000 foundations and corporations. The council named him Distinguished Grantmaker that year.

“There was nothing abstract in Bob’s lifelong commitment to social justice: It arose out of the deepest feeling for the lives and possibilities of people too easily and often overlooked or pushed aside, and it was everywhere seasoned with realism, humor, and a genuine love for the push and pull — the real social work — of getting things done,’’ the trust’s chairman, Stephen Melville, said in a statement.

Mr. Hohler’s passion for social activism began as a teenager when he joined a youth group at the Unitarian Universalist Arlington Street Church in Boston, and it soared during the civil rights movement.