Did not attend any other conventions
A collective biography of these men? (What did they have in common?)
Harbison was the son-in-law of Isom Gaines and Elizabeth Clark Gaines. See:
Walters, Delores M., Mary E. Frederickson, and Project Muse, eds. Gendered Resistance: Women, Slavery, and the Legacy of Margaret Garner. New Black Studies. Urbana: University of Illinois Press, 2013.
On Tolliver, see:
Centennial Encyclopaedia of the African Methodist Episcopal Church, Page 350 | Document Viewer. Accessed February 7, 2016. http://www.mocavo.com/Centennial-Encyclopaedia-of-the-African-Methodist-Episcopal-Church/426462/350.
R. G. Ball, daguerrotypist (probably son of J. P. Ball?)