Robert McCullough, who led a group of black students in a landmark 1961 civil rights protest, choosing to serve jail time on a chain gang for the crime of sitting at a whites-only lunch counter, died Monday in Rock Hill, S.C. He was 64. The cause was unknown as of press time.

McCullough, along with eight other black students from Friendship Junior College, gained widespread attention when they used the “jail, no bail” technique after they were arrested in February 1961.

The protesters, who became known as the Friendship Nine, had demanded service at the McCrory’s lunch counter at Rock Hill, and were charged with trespassing and breach of peace. The protest came around the first anniversary of a sit-in at another segregated lunch counter, in Greensboro, North Carolina, that helped galvanize the civil rights movement.

Given the option of paying a $100 fine or serving 30 days in jail, the Rock Hill students broke with earlier sit-in protesters and chose to serve the time, even though it meant a frightening ordeal on a chain gang.

The Rock Hill group’s sacrifice “made electrifying news” within the protest movement, author Taylor Branch wrote in his book “Parting the Watrers: America in the King Years 1954-63.”

“The obvious advantage of ‘jail, no bail’ was that it reversed the financial burden of protest, costing the demonstrators no cash while obligating the white authorities to pay for jail space and food,” Branch wrote.