From whence does this union rise? Communion of Saints. First found in J. Asplund's New Collection, Baltimore, 1793, beginning, "O whence does this union rise." Formerly very popular, and still in use as in the Baptist Hymn [and Tune] Book, Phila., 1871, No. 638. In the Church Pastorals, Boston, 1864, No. 981, it is altered to "From whence doth this union arise.” [Rev. F. M. Bird, M.A.]
-- John Julian, Dictionary of Hymnology (1907)