1. Spies, Scouts, and Secrets in the Gettysburg Campaign: How the Critical Role of Intelligence Impacted the Outcome of Lee's Invasion of the North, June-July 1863 by Thomas J. Ryan (Savas Beatie, 2015).
With books covering Pickett's Charge, the Cyclorama, Second Winchester, this one examining the role of intelligence during the campaign and others, the Savas Beatie Summer of Gettysburg is upon us. Ryan's book describes and analyzes Lee's information gathering networks and how they influenced his management of the Pennsylvania campaign. Same with those of Hooker and Meade, including the Bureau of Military Information and the Signal Corps. Looks like a must-read for the hardcore Gettysburg person.
2. For the Union and the Catholic Church: Four Converts in the Civil War by Max Longley (McFarland).
William S. Rosecrans would probably be considered by most to be the Civil War's most prominent Catholic soldier. His story and that of three other 1840s converts who supported the Union cause (the general's brother Bishop Sylvester Rosecrans, first black priest ordained in the U.S. Father James Healy, and the Quarterly Review's Republican editor Orestes Brownson) are chronicled in this book.