More than 65,000 Union soldiers had been killed that summer.
Explanation:
Lincoln was concerned about the possibility of Grant running in the 1864 presidential election.
With the help of a mediator, he questioned Grant's political intentions and, when he was satisfied they were gone, proposed to the Senate Grant's promotion to Union Army commander.
He won Congressional approval that Grant receive the rank of lieutenant general, who by then had none except George Washington.
This was hardened by many people who have died that summer.