From NPR: When he arranged the date at Folsom, Cash at least knew he'd have a captive audience. "One thing he liked about playing prisons: If he did something the audience didn't like, they couldn't leave," W.S. "Fluke" Holland, Cash's drummer at the time, says. Holland didn't expect much would come of the two sessions the band played that day. "That shows how wrong I was."
When the album At Folsom Prison was released the following May, it topped the Billboard country charts and Cash's career took off again. He recorded another best-selling album from San Quentin Prison in 1969.
Sidd