He was the only Confederate General that President Johnson (not LBJ), would not offer reconciliation to.
When U.S. Grant was elected President, he summoned Longstreet to the White House, returned citizenship to him, and set him up with a job.
I wish that story was more widely known - Grant doesn't even mention it in his autobiography, (much too humble).
Longstreet was later reviled among hard ex-Confederates. He became a Republican.
The loss at Gettysburg was avoidable. The last day at Gettysburg was clearly avoidable. Lee should have moved, and picked his ground.
To this day, with Vicksburg under siege, I never understood why Lee went North instead of moving on Grant. Perhaps it’s just his genius that I don’t understand.