A crowd of about 300 mourners gathered at the Community Church of New York in Murray Hill to celebrate the life of Donald Harrington, the Unitarian minister and longtime state chairman of the Liberal Party who was one of the city’s most visible social and political activists for decades.

“I can testify that South Africa’s diplomacy in New York began in this building,” the South African permanent representative at the United Nations, and a Sunday school teacher at the Community Church for many years while in exile from the apartheid regime, Dumisani Kumalo, said.

Harrington, who died September 16, co-founded the American Committee on Africa in 1952, which for many years had its headquarters at the Community Church. The committee was an early supporter of the African National Congress.

“Here at Community Church, one could talk about Selma and Soweto without having to stop and explain the geographical location and political significance of these places,” Mr. Kumalo said. “This was the church were you could listen to Malcolm X and Bayard Rustin debate the impact of racism in America.”

In 33 years as a senior minister, Harrington was responsible for the Community Church nurturing dozens of liberal and civil rights groups, including the American Indian Community House, Student Nonviolent Coordinating Committee, and the Congress of Racial Equality.

An early leader of CORE, George Hauser, recalled yesterday that Harrington was a supporter of the group during his days at the People’s Liberal Church in Chicago, in the early 1940s. Harrington came to the Community Church in 1944 and retired in 1982.

Also speaking at the memorial was Harrington’s daughter, Loni Hancock, who recalled playing among the pews of the Scandinavian modern style church – whose construction Harrington oversaw soon after coming to New York – while her father preached in Emersonian cadences. Ms. Hancock served as mayor of Berkeley, Calif., and is currently a California Assembly member.

Ms. Hancock said her father was unafraid to go against the grain of received liberal opinion when his conscience so dictated.

The president and CEO of Harlem Congregations for Community Improvement, Lucille McEwan, recalled that during the point in the civil rights movement when many in his denomination supported black separatism, Harrington insisted that a racially integrated approach would be most effective. In 1968, he cofounded Black and White Action, a Unitarian-Universalist group devoted to integration. In this, Harrington was continuing the tradition of his predecessor at the Community Church, John Haynes Holmes.

“He combined intellection with high preaching power,” a pacifist and former Sunday school student who has been a congregant for nearly a half century, Robert Reiss, said.