1. Guerrilla Warfare in Civil War Missouri, Volume IV, September 1864 - June 1865 by Bruce Nichols (McFarland, 2014).
The final volume of Nichols's essential reference series, this book begins with the irregular activities coinciding with the Price Raid and ends with the war's conclusion.
2. So You Think You Know Gettysburg? Volume 2 by James and Suzanne Gindlesperger (Blair Pub Co, 2014).
The Gindlespergers's first Gettysburg travelogue So You Think You Know Gettysburg? The Stories behind the Monuments and the Men Who Fought One of America's Most Epic Battles covered 200 related sites in historical narrative, pictures and maps. Volume 2 looks at another 200+ sites. They also have an Antietam book.