American social activist Reverend William Sloane Coffin, known for for his fight against segregation and the Vietnam War, has died at the age of 81.

The former Yale University chaplain died Wednesday in Vermont.  He had been suffering from congestive heart failure.

Coffin gained prominence in the 1960s during the American civil rights movement, speaking out against and challenging segregation laws.  He was also actively opposed to the war in Vietnam.  

Coffin mobilized acts of civil disobedience, and lead a demonstration where Army resisters turned in their draft cards.  He was arrested several times for protests.

After leaving Yale, Coffin ministered at a New York City church, then moved to Vermont and continued to lecture on social issues.

Coffin was immortalized as the "Rev. Sloan" character in the Doonesbury comic strip created by Yale graduate Garry Trudeau.

Some information for this report was provided by AP and Reuters.