Sixty-six years ago today (April 2, 1956) was a career-changing day for Johnny Cash: It was on that date that he recorded "I Walk the Line," for his freshman album, With His Hot and Blue Guitar.

"I Walk the Line," which became the third single from Cash's debut record, shot straight to No. 1 when it was released on May 1, 1956. Written by Cash and recorded at Sun Studio in Memphis, Tenn., the song's title was suggested by fellow country artist Carl Perkins. Cash wrote the lines, including "As sure as night is dark and day is light / I keep you on my mind both day and night / And happiness I've known proves that it's right / Because you're mine, I walk the line," with his then-wife, Vivian Liberto, in mind.

Johnny Cash I Walk the Line single
Sun Records

"I wrote the song backstage one night in 1956 in Gladewater, Texas," Cash said. "I was newly married at the time, and I suppose I was laying out my pledge of devotion."

Cash said that he wrote "I Walk the Line" in 20 minutes: "The lyrics came as fast as I could write," he recalled.

"I Walk the Line" became one of the most iconic songs for the Man in Black. In addition to its country success, it reached the Top 20 on the pop charts; was the title of a 1970 Gregory Peck movie; and was also the title for the 2005 film, starring Reese Witherspoon and Joaquin Phoenix, about Cash's life.

Cash re-recorded "I Walk the Line" in 1964, for his I Walk the Line album; in 1969, for his At San Quentin album; in 1970, for the I Walk the Line soundtrack; and in 1988, for his Classic Cash: Hall of Fame Series. Several artists have also covered the song, including Rodney Crowell and Craig Wayne Boyd, the latter of whom performed it on Season 7 of The Voice.

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