I’ve been reading more about John Brown’s Raid, and came across this first-hand account. The author, Osborne Perry Anderson, was the only surviving African-American who took part in the raid. Google has provided scans of the original book in its entirety (isn’t the Internet great?) I’ll add it to The Library.

http://books.google.ca/books?vid=07O-FNwsAHVDjCS26XVa-y&id=sUxp11UMkBMC&printsec=titlepage&dq=Osborne+Anderson%7CA&redir_esc=y#v=onepage&q=Osborne%20Anderson%7CA&f=false