I strongly recommend the “Gettysburg” trilogy by Newt & Bill Forstchen.
It’s a “what if” the South had won at Gettysburg, & they REALLY get Grant.
Just finishing up Ron Chernow’s biography of Grant.
Honestly a hard book to put down.
Read it, good writing.
In Longstreet’s memoirs he talks about a plan he had in the spring of 1863. The reason he wasn’t at Chancellorsville was he had taken two divisions south by rail to forage the areas of coast under Federal control. At the time Grant had Vicksburg under siege, and Gen. Joe Johnston was trying to gather men at Corinth to break it, but only had about 30,000 men, not enough to break through Grant’s double sided siege works. Gen. Bragg had another 50,000 facing the Union Army of the Cumberland with 60,000 near Chattanooga. His idea was to take advantage of railroad and interior lines of communication to take his corps to Atlanta by rail within a couple of weeks. At the same time troops would be pulled from coastal garrisons, and Johnston would also move to join with Bragg’s army. The combined force would smash the Army of the Cumberland, then move north through Kentucky into Ohio. Grant would have no choice but to abandon Vicksburg and move north. Longstreet said by July 1st he could have 150,000 troops on the banks of the Ohio River. Now that would be an interesting “what if?”.
As it turned out by the time he got back Lee had already received approval for his invasion of Pennsylvania so he never presented the plan. A smaller version was adopted later when his corps was sent south resulting in the Confederate victory at Chickamauga.