KimC, (as you know, but mentioned here for newbies) a number of the spirituals from Allen's 1867 collection have been posted here, along with references to this docsouth site. See African-American Spirituals permathread. In the online text go to p. XXXIX for an index.
Also on Univ. North Carolina docsouth, is Fenner's collection from 1874. Cabin-Plantation songs Scroll to p. 256 for an index. Most of these were published in editions of "Religious Folk Songs of the Negro" and were sung by the Hampton Singers. Some of these also posted here and listed on the Spirituals Permathread.
Higginson's Negro Spirituals, 1867, is also on line at Negro Spirituals Thiry-seven songs including Many Thousand Go and Hangman Johnny. Other interestin texts are at this University of Virginia site.

All of this is repetition; these sites are mentioned in a number of spirituals threads posted over the past year or so, but they bear repeating.