I had a privilege of accepting surrender of my CSA opponent in the historic battle of Antietam after just 16 turns.
Now, I don't consider myself some sort of strategic prodigy but I found a strategy that worked really well against defensive minded Confederate. Early in the game, and before their reinforcements arrive, Confederates really have few options except to sit tight. Any probe or pushing their pickets forward might trigger fixed Union units. This offers early window of opportunity and I exploited that by swinging Hooker & Mansfield (I & XII) towards the Potomac River and straight south with intention of turning the Confederate flank. I left Porter and Burnside (V & IX) to hold the center and south, and no I didn't go anywhere near the bridge with Burnside
My calculation was that if Confederates push against V & IX the Union forces would have plenty of space to defend in depth, at the same time that would leave the troops opposing the aforementioned I & XII without reinforcements. If however the Confederates turned his reinforcements north I planned to concentrate V & IX in the center and drive straight for town of Sharpsburg, the ridges giving superior position for my artillery. Now, that still left Sumner & Franklin at large (II & VI) both were sent to reinforce the northern trust with option of engaging the Confederate main body if they chose to interfere with light screening units. I had only one stretched out division in single line but they were intended to act more as a delay than all out blockade.
In the end my fast moving with I & XII caught the bulk of Confederate artillery in the north resulting in destruction or capture of about a dozen batteries and majority of Confederate cavalry (JEB Stuart POW) that tried to delay my infantry. I advanced in columns for speed and speed compensated for the losses I received. The Confederate reinforcements stopped my advance NW of Sharpsburg but within a cannon shot of the town. At that time Sumner was arriving, Franklin started to move but sadly most of Porter and Burnside troops were still fixed.
Casualty ratio was 2.5 to 1 for infantry, about 1.500 to 0 for cavalry and and about 20 or so batteries taken or destroyed for the price of one. With Sumner (French's division in vanguard) poised to attack in force around Dunker church, the Confederate commander opted to surrender.
While wedging two corpses between a river and enemy army might look a bit risky I found it to be great opening strategy. Especially since I & XII thus bypassed Confederate defenses in West Woods.
I have to admit though that my opponent preferred to move in mass thus often leaving his flanks very lightly defended.
