Some books that are coming out, some soon, and some are far enough out that I don't yet know the titles...
Meade and Lee at Bristoe Station: The Problems of Command and Strategy after Gettysburg, from Brandy Station to the Buckland Races, August 1 to October 31, 1863
Jeffrey Hunt
Why yes, that is a very long title. This is the second of three volumes addressing a generally neglected period - what did Meade and Lee do in the months right after Gettysburg? The previous volume is
Meade and Lee After Gettysburg: The Forgotten Final Stage of the Gettysburg Campaign, from Falling Waters to Culpeper Court House, July 14-31, 1863. Why yes, that is another very long title. The new volume is available for pre-orders right now although the ETA is uncertain.
New biography of Frederick Douglass
David Blight
Blight is one of the more significant modern historians and writers, and this book is squarely in his area of specialty.
New biography of Robert E. Lee
Allen C. Guelzo
Guelzo is another top historian and writer, and this book should fill a major hole. There is a dire need for a good modern biography of Lee (the Korda book from 2014 does not qualify in my view.) While waiting,
Reading The Man by
Elizabeth Brown Pryor is a good way to learn about Lee.