Chapter two of Cifford Dowdey's Death of a Nation: The Story of Lee and His Men at Gettysburg reviews the cabinet meeting at Richmond on May 14-15, 1863. Here President Davis discussed military alternatives with Robert E. Lee and his cabinet members. Chapter three includes a discussion of opposing plans Lee and Davis had for four of five brigades of Pickett's Division left at Hanover Junction. Initially Davis wanted all of them left at the junction; based on an agreement with Secretary of War Seddon, Lee expected Corse's Brigade to be released to join the other three marching north with his army.
Unfortunately Davis overruled Seddon, and the brigade of Micah Jenkins was retained on the Blackwater River. In addition Lee had expected Henry Heth's Division to be completed by addition of two veteran brigades. Instead, Davis sent two untested brigades, one led by Johnston Pettigrew and the other by Joseph Davis. Thus Lee was deprived of four brigades from his army in exchange for two new ones.