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From the wiki article:In the Southern gospel genre the song is often associated with Luther G. Presley, who wrote the lyrics, and Virgil Oliver Stamps, who wrote the music, whose version copyrighted by the Stamps-Baxter Music Company popularized it as a gospel song. A similar version was copyrighted by R.E. Winsett. and: The song is sometimes confused with a similarly titled composition "When the Saints are Marching In" from 1896 by Katharine Purvis (lyrics) and James Milton Black (music).[1]