IIRC, Lee quit the war briefly to go execute his father-in-law’s will and free his slaves.
Actually that began well before the war. Lee was granted a lengthy leave of absence to execute his FIL’s almost impossibly complex will. At the end of his leave of absence while the terms of returning Arlington Plantation to being a paying proposition before the plantation’s slaves could be manumitted, By Virginia law private manumissions were illegal, a complicated and demanding manumission package had to be moved through the legislature. (Following the Nat Turner insurrection manumission of slaves was no longer a private matter.) A heavy financial responsibility bond had to be executed by the owner to guarantee the freedman would not become a public charge this had to be accompanied by a detailed statement of the good conduct and moral character of each slave to be freed. This is because it was believed that malcontent freedmen had been partially responsible for Nat Turner absorbing some of his radical beliefs. After quashing the John Brown terrorist raid Lee had to return to his command in Texas. He came back to Virginia in March 1861 and resigned his commission. The Va legislature cleared the manumission package of Lee in part as he was now commander of Virginia state forces. The Arlington slaves were freed just as the war began and were given land to settle on that had been part of the plantation. To this day this area known as Arlington Heights is mostly populated with decendents of these freedmen and continue to work for the administration of Arlington Cemetaery and Fi Myer.