I think "The Peninsula Campaign & the Necessity of Emancipation", by Glenn David Brasher, would have been an excellent 150 page book, but is less satisfying as a 300 page book. Mr. Brasher describes the various ways in which Southern slaves proved helpful to Union troops in the Peninsula Campaign in Virginia early in the Civil War. In making his point(s) however, Mr. Brasher overwhelms the reader with repetitive references to various newspapers, long forgotten soldiers, and numerous politicians repeating very similar information over and over again. That's valuable to prove one's point, but doesn't lend itself to a moving narrative.
The book does not, and is not intended to provide a complete chronological review of the Civil War, militarily nor politically, but rather focuses specifically on the interaction of the slaves in the Virginia peninsula during General McCellan's early attempts to capture Richmond. The activities of the slaves in helping Confederate troops, and of their value to Union troops, ultimately helped to convince many Northerners that emancipation was a military necessity. It was interesting to see how political pressure for emancipation influenced Lincoln's decision to issue the Emancipation Proclamation after the Peninsula Campaign to take Richmond failed early in the War. ( )