On Jan. 13, 1968, after two days of rehearsals in a Sacramento motel, Johnny Cash and June Carter, along with the Statler Brothers, Carl Perkins and the Tennessee Three, entered Folsom State Prison in Folsom, California. Cash held two concerts for the inmates, one in the morning and one in the afternoon. Many of the songs were prison-themed, from the opening “Folsom Prison Blues” to the execution countdown “25 Minutes to Go.”