Wholesale Ghosts of Time by Steve White

[Baen] Book #4 of the Jason Thanou Time Travel series. Jason and his team travel to the latter days of the American Civil War to combat a transhumanist threat. Sequel to Pirates of the Timestream. Special operations officer Jason Thanou of the Temporal Regulatory Authority must once again plunge into Earth’s blood-drenched past to combat the plots of the Transhumanist underground to subvert that past and create a secret history leading up to the fulfillment of their mad dream of transforming humanity into a race of gods and monsters. The transhumanists are attempting to use the chaos of the American Civil War to escape the Observer Effect: the immutable law that recorded history cannot be changed. If any should attempt it, time has a way of dealing with those transgressors in a very brutal, very final fashion. Now it is the last days of the Confederacy, and the Fall of Richmond looms. In the Shenandoah Valley, in the region later known as Mosby’s Confederacy, insurgency bre