When Merle Haggard sings about life behind bars, he's playing three chords and the truth. He served almost three years in California's maximum-security facility San Quentin for burglary before being paroled in 1960. But while Haggard may have been free from his cell, he continued to carry the stigma of being a "branded man." Instead of regressing to previous bad behaviors, however, he channeled both his experience inside and out of the prison walls into some of country music's most evocative songs: "Sing Me Back Home," "I'm a Lonesome Fugitive" and, of course, "Mama Tried." Today, as country fans note the Hag's 78th birthday, we count down his 12 most badass prison songs.