Lee invaded Maryland, and McClellan, restored to command of the Army of the Potomac, followed him, and found a copy of his order of march, which revealed the fact that only a portion of the army was before him. So, overtaking the Confederates at South Mountain, he was ready for a victory, but waited one day; and in the mountains Lee got his troops united again, while Jackson also returned. The Union troops had over eighty thousand in their ranks, and nothing could have been more thoughtful or genteel than to wait for the Confederates to get as many together as possible, otherwise the battle might have been brief and unsatisfactory to the tax-payer or newspaper subscriber, who of course wants his money's worth when he pays for a battle.