We all know Johnny Cash as the country crooner, but we rarely hear the story of his first marriage. Now hundreds of love letters, vintage photographs, and home movies come to light in My Darling Vivian, a new documentary focusing on the life of Johnny, his wife Vivian Liberto, and their four daughters.

In the film, out digitally through Film Forum in New York, Laemmle Theaters in L.A., and other participating theaters across the U.S. and Canada, Rosanne, Kathy, Cindy, and Tara Cash share family memories from the star’s largely forgotten 13-year marriage, uncovering an intimate chapter of Johnny’s life. From family pets to bedtime stories and birthday parties, the sisters dish on what their dad was like before he got heavy into drugs and disappeared to New York, rooming with Bob Dylan in SoHo.