“Peggy Sue” was a top ten hit in New Zealand in March, 1958.
"Peggy Sue" reached the top ten of the United States and United Kingdom charts. Buddy Holly and the Crickets toured Australia in January 1958 and the UK in March.
Their third and final album, That'll Be the Day, was put together from early recordings and was released in April.
In the liner notes to Buddy Holly: The Definitive Collection, Billy Altman notes that "Peggy Sue" was originally written as "Cindy Lou" (after Holly's niece), but Holly changed it prior to recording as a tip of the hat to Crickets drummer Jerry Allison's girlfriend, Peggy Sue Gerron. Allison wanted the song to be named after Gerron to make up for a recent fight. The two later married!