Thanks to all who commented on the original post.
Some highlights from the readers:
Edward Steere The Wilderness Campaign: The Meeting of Grant and Lee and Richard Moe The Last Full Measure: The Life and Death of the First Minnesota Volunteers.
Edwin B. Coddington The Gettysburg Campaign: A Study in Command.
James V. Murfin The Gleam of Bayonets: The Battle of Antietam and Robert E. Lee's Maryland Campaign, September 1862.
George R. Stewart Pickett's Charge, David Hinze & Karen Farnham The Battle Of Carthage: Border War In Southwest Missouri, Alice Rains Trulock In the Hands of Providence: Joshua L. Chamberlain and the American Civil War, Christopher Losson Tennessee's Forgotten Warriors: Frank Cheatham and His Confederate Division and William D. Matter If It Takes All Summer: The Battle of Spotsylvania
J. Tracy Power Lee's Miserables: Life in the Army of Northern Virginia from the Wilderness to Appomattox
Phil Gottschalk In Deadly Earnest: The History of the First Missouri Brigade, CSA .