I recently completed To Antietam Creek by D. Scott Hartwig. I bought it based on the recommendation of some of our members and was not disappointed. The movements of the troops, whether on the march or in battle, are clearly spelled out. Hartwig blends his narrative with numerous primary witness accounts. The maps add clarity to the narratives. I will note that this is a very in depth book, not for someone not versed in the basics of the campaign. If you are interested in a detailed account of the run up to the Battle of Antietam this book is hard to beat. I'm looking forward to part two.
Next up - volume 3 of David Powell's Chickamauga trilogy: The Chickamauga Campaign—Barren Victory: The Retreat into Chattanooga, the Confederate Pursuit, and the Aftermath of the Battle, September 21 to October 20, 1863