My bad it was published in 1867 not '66, and its written by Horace Greeley of all people.
Online at.... http://books.google.com/books?id=rVEMAAAAYAAJ&printsec=frontcover&dq=The+American+Conflict&as_brr=3&ei=YPTYS9LQNoOUkATv5o3bCA&cd=1#
The American conflict: a history of the great rebellion; Chapter XXII Page 511 Is the start of a very good chapter and 521 starts the coverage of Confederate Black soldiers.
David