Yes, I read Chuck's article. So then whose slaves did Lee free in 1862 if not his own? And where is the evidence that Grant owned a single slave past 1859?
They were his father-in-law's slaves. In his will, George Washington Parke Custis stipulated that all the Arlington slaves should be freed upon his death if the estate was found to be in good financial standing or within five years otherwise. However, upon his death Custis left a good number of debts that still needed to be paid off, which resulted in the slaves not being freed immediately per the will. This was done in order to pay off his father-in-law's debts, not out of a desire to own slaves. In a letter to President Pierce, Lee wrote that "There are few, I believe, in this enlightened age, who will not acknowledge that slavery as an institution is a moral and political evil."
You are correct that Grant freed the slave that was under his name in 1859. However the family owned four others under his wife's name, although Grant himself was responsible for supervising them. That being said, of course, in that day and age, meant Grant was in control of them. These slaves were not freed until 1865 when Missouri officially abolished slavery.
“So then whose slaves did Lee free in 1862 if not his own?”
His wife’s.