Vivian was the national director of some 85 local affiliate chapters of the S.C.L.C. from 1963 to 1966, directing protest activities and training in nonviolence as well as coordinating voter registration and community development projects.
In Selma and Birmingham, Ala.; St. Augustine, Fla.; Jackson, Miss.; and other segregated cities, Mr. Vivian led sit-ins at lunch counters, boycotts of businesses, and marches that continued for weeks or months, raising tensions that often led to mass arrests and harsh repression.
Televised scenes of marchers attacked by police officers and firefighters with cattle prods, snarling dogs, fire hoses and nightsticks shocked the national conscience, legitimized the civil rights movement and led to passage of the Civil Rights Act of 1964 and the Voting Rights Act of 1965.
“Nonviolence is the only honorable way of dealing with social change, because if we are wrong, nobody gets hurt but us,” Mr. Vivian said in an address to civil rights workers, as recounted in “At Canaan’s Edge: America in the King Years, 1965-68” (2006), by Taylor Branch. “And if we are right, more people will participate in determining their own destinies than ever before.”
Cordy Tindell Vivian was born in Boonville, Mo., on July 30, 1924, the only child of Robert and Euzetta Tindell Vivian. His family moved to Macomb, Ill., when he was 6, and he later graduated from Macomb High School in 1942. He studied history at Western Illinois University in Macomb, but he dropped out and became a recreation worker in Peoria, Ill., where he joined his first protest, in 1947, helping to desegregate a cafeteria.
In 1945, Mr. Vivian married Jane Teague, who worked at a hardware store, and they had one daughter, Jo Anna Walker, who survives him. The couple separated amicably in the late 1940s and divorced later so that Mr. Vivian could marry Octavia Geans, in 1952. She was the author of “Coretta” (1970), the first biography of Dr. King’s wife, Coretta Scott King. She died in 2011.
In addition to his daughters Kira, Denise and Jo Anna, Mr. Vivian is survived by another daughter, Anita Charisse Thornton; two sons, Mark Evans Vivian and Albert Louis Vivian; nine grandchildren; 10 great-grandchildren; 28 great-great-grandchildren; and two great-great-great-grandchildren. Another son, Cordy Jr., died in 2010.