Interestingly, the high losses at Antietam were what prompted Lee to invade western and southern Pennsylvania the following year as he knew the south couldn't win a protracted peace. June 1863 was an interesting month in western and southern Pennsylvania history. Lee's army burned military targets such as the steel works outside of Pittsburgh, but generally behaved in civil fashion otherwise. There is one episode where he sent a cavalry unit commander back to a storekeeper to apologize and pay for headgear they had rather forcibly "traded" to acquire. Quite the contrast to Sherman's army's behavior on their march from Atlanta to Savannah.
“Lee’s army burned military targets such as the steel works outside of Pittsburgh”
Pittsburg is 195 miles from Gettysburg. It is on the West side of the Appalachian Mountains, Gettysburg is on the East side. Doubt Lee sent raiding parties that far away from his army.