There is a bit on the provenance of 'We Shall Overcome' at the following link. It cites Tindley's 'I'll Overcome Some Day' as the original inspiration. The full text of Tindley's hymn may be found at the Cyber Hymnal site.Evidently the great gospel singer, Marion Williams, did a belter of a version taking the civil rights song back to its gospel roots, but I cannot find it among the recordings I have of her.
--Stewie.