Regarding the thread title-- internationally, the term people use for this body of music is "Negro Spirituals." This places the genre in time, and distinguishes it from "White Spirituals." No disresepct is intended by this thread title.
In the index, we also list songs that may have been based on, or thought by some to be, "Negro Spirituals" to make comparison and study easier. Blues and blues-gospel songs that sound like (or are thought to be based on) spirituals are indexed there as well.
The third edition of the index is up now, HERE.