[Sherman Logan]

Lincoln would relieve George Meade, a perfectly competent if unaggressive general, for letting Lee escape over the Potomac with his army bloodied but still intact.

He did not. Meade commanded the Army of the Potomac for the rest of the war.

Grant was General in Chief of all US forces, though with his headquarters with the A of P.

[Ditto]

He did not. Meade commanded the Army of the Potomac for the rest of the war.

I was about to post the same Sherman. It's a misconception that Grant replaced Meade as head of the Army of the Potomac. Grant replaced General Henry Halleck as general-in-chief -- i.e., the head of all the US Armies, not just the Army of the Potomac. It was the same position that the Chairman of the Joint Chiefs of Staff holds today.

Meade was the commander of the Army of The Potomac until the end of the war.