WILLIAM SLOANE COFFIN, civil rights campaigner and chaplain of Yale during the tumultuous years of the Vietnam war, made a lifelong career of civil disobedience. Calling himself a “Christian revolutionary”, throughout his 18-year tenure at Yale he inspired a generation of students in his resistance to the war and his campaign against segregation.

Appointed to the Yale chaplaincy in 1958, he was a tall, handsome man who sped around the campus on his motorcycle, signalling that his presence would herald a radical new approach.

Coffin was one of the first white Northerners to join the Freedom Riders, who travelled through the South on interstate buses, monitoring enforcement of civil rights laws. He was arrested in Alabama during a demonstration against segregated bus stations, and again in Maryland and Florida. “You’ve got to be rugged and determined and expect to take hard knocks if you’re going to do a Christian’s work in the world,” he told a reporter.

Asked him about his frequent run-ins with the law, he said: “I don’t go around picking fights. Some fights pick you.”

In 1967 Coffin and Dr Benjamin Spock led a demonstration in Boston at which nearly 1,000 men handed over their military draft cards in an anti-Vietnam war demonstration. They were subsequently convicted of conspiracy to aid and abet disobedience of the Selective Service Act, but the charges were later overturned.

By that time Coffin’s name was known throughout America and he was caricatured as the ultraliberal Rev Scot Sloan by cartoonist Gary Trudeau in his Doonsbury strip. Trudeau once said of Coffin: “Without him, the very air would have lost its charge. With him we were changed forever.”

“Walking through the streets of Newhaven with William Sloane Coffin Junior is like being in a movie about a small-town folk hero,” wrote Jessica Mitford. “People come up to shake his hand, students run after him with urgent questions, old folk stop their cars to call out ‘Good luck, Bill’ and ‘Howdy Reverend’.

The spectacle of the chaplain of an Ivy League university counselling students that they were right to resist the draft so infuriated the Johnson Administration that Attorney-General Ramsey Clark, himself a prominent liberal, sought to imprison Coffin. The chaplain caused further outrage when he offered draft dodgers sanctuary in the Yale chapel.

William Sloane Coffin was born into a prominent Manhattan family in 1924. His father was the president of the trustees of the Metropolitan Museum of Art. Coffin studied music in Paris and later at the Phillips Academy at Andover, from which he graduated in 1942, followed by a year at Yale music school. He then entered the Army and was sent to Europe as an infantry officer.

In 1946 he was involved in the forcible repatriation of Soviet citizens who had been taken prisoner; many were never heard of again. He later wrote a memoir entitled Once to Every Man, in which he spoke of “the burden of guilt I am sure to carry the rest of my life” over his role in the operation.

“It influenced my decision in 1950 to spend three years in the CIA, opposing Stalin’s regime,” he wrote. In Germany he helped to parachute anti-Soviet Russians into the country to work against the regime in paramilitary teams. “It didn’t work,” he later told the New York Times. “It was fundamentally a bad idea. We were quite naïve about American power.”

He returned to the US in 1953 to study at Yale Divinity School, graduated in 1956 and returned to Andover as school chaplain. In that year he married Eva Anna Rubenstein, an actress and dancer and the daughter of the pianist Artur Rubenstein. The couple had three children before the marriage ended in divorce in 1968.

Coffin remained chaplain of Yale until 1976 when he stepped down to work with world hunger programmes and to write his memoir. A few months later he divorced his second wife, Harriet Gibney, and married Virginia Randolph Wilson. In 1978 he was appointed to the ministry at Riverside Church, New York, where he promoted international arms control and focused his ministry’s attention on the plight of the poor.

In his later years he devoted himself to anti-war crusades, advocating a nuclear freeze, opposing the 1991 Gulf War and speaking out against the invasion of Iraq in 2003. However, he did not consider himself a pacifist, and when genocide broke out in Bosnia he asserted that there were times when international intervention with force was justified. He once preached at Riverside Church on the “huge difference between patriotism and nationalism”.

“Patriotism at the expense of another nation is as wicked as racism at the expense of another race,” he declared. “Let us resolve to be patriots always, nationalists never.”

In 1999 he suffered the first of several strokes, but he continued to campaign and to participate from his wheelchair in public protests.

He is survived by his third wife, and by two children from his first marriage.

The Rev William Sloane Coffin, pastor and activist, was born on June 1, 1924. He died on April 12, 2006, aged 81.