Early in the morning on June 1, 1953, five African American men boarded a van to make the 200-mile trip from Nashville to Memphis for a daylong recording session at the legendary Sun Studios, to be overseen by Sun founder Sam Phillips. One of the two tracks cut that day, "Just Walkin' in the Rain," would go on to become a regional R&B hit, Sun Records' biggest record of the pre-Elvis era. It would, however, be the group's only hit. They were...