The song "When the Saints Go Marching In" originated as a traditional Christian hymn, likely written in the late 1800s or early 1900s. Early versions of the song appeared in recordings from the 1920s, with the best- known jazz rendition by Louis Armstrong recorded on May 13, 1938. The song evolved from slower gospel versions into a vibrant jazz standard associated especially with New Orleans. It has since become a widely recognized and beloved tune in both religious and jazz music contexts, celebrated for its imagery related to the Last Judgment and the desire to be among the saints entering heaven.