Antietam 1862 AAR

[rhinobones]

Antietam 1862 Introduction

Antietam 1862 is an ACW scenario designed by Steve Sill. It is a single engagement with limited objectives but still provides the flavor of the muzzle loading era. Other scenarios in the series offer more extensive battles and longer engagement time, but for this AAR I’m looking for a first-time experience which does not require a long-term commitment. For myself, anything over 25 turns constitutes long-term.

I will be playing the CSA side against the Union Programmed Opponent.

The Scenario

The scenario depicts CSA occupied Sharpsburg assaulted by the Union Army of the Potomac. The focal point of the battle is Sharpsburg which provides the occupying side with 25 Victory Points. Initial Union and CSA deployments are shown below.

Intro – Initial Deployment.jpg (318.94 KiB) Viewed 1598 times

The deployed forces are tilted a little to the Union side which seems appropriate as they will be the aggressors. The scenario is rated on the low end of the published complexity scale. However, my personal measure of scenario complexity differs in that it is a function of total formations, maneuver units and actionable events, i.e. Theater Options. For this scenario there are no Theater Options but the count of formations and units is:

Union: 7 Formations and 24 Units
CSA: 12 Formations and 19 Units

From my perspective this scenario is at the bottom of the complexity scale. It is, however, a genre in which I rarely enjoy and a subject I find very interesting. That makes it exactly the type of scenario I’m looking forward to playing.

Intro - Forces.jpg (258.16 KiB) Viewed 1598 times

I expect that the scenario has been designed to replicate the historical engagement at Sharpsburg with the strategic movements and objectives programmed into the opponents. If I am able to maintain control of Sharpsburg, then I’ll achieve the historical outcome even if at a devastating cost in casualties. The challenge will be to use the tactics of attack and defense to inflict maximum casualties while holding the objective.

The battle begins with the Army of the Potomac moving on to the CAS position.

[Curtis Lemay]

Antietam 1862 Introduction

Antietam 1862 is one in a series of ACW scenarios designed by Bob Cross.

Actually, the scenario shown is Steve Sill's - Division scaled. Mine is called "Sharpsburg 1862" - Brigade scaled:

https://www.matrixgames.com/forums/view ... 4#p4941174

[rhinobones]

Actually, the scenario shown is Steve Sill's - Division scaled. Mine is called "Sharpsburg 1862" - Brigade scaled:

Thank you for the correction. Shows that it’s important to go to the bottom of the page and read the fine print.

Regards

[rhinobones]

Turn 1 Union

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The scenario was started in the “Head-to-Head” mode then switched to Union PO as directed in the briefing.

The opening Union move is against Jackson’s divisions guarding the CSA left flank. Other Union units are briefly observed maneuvering to the Northeast but are not yet in position to engage the rebels.

T1 – Union Battle Losses.jpg (157.37 KiB) Viewed 1524 times

Jackson’s divisions hold the northern left flank against several Union assaults. Total casualties are about 2 to 1 in favor of the CSA.

[rhinobones]

Turn 1 - CSA

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CSA activates the “Take full control of CSA forces” Theater Option in accordance with the briefing.

Units are redeployed to counter possible Union maneuvers. A division from Lees Reserves is moved to guard the far-left flank. This route leads directly to Sharpsburg and the Union main objective. This is expected to be an obvious line of Union attack. J.E.B. Stuart’s cavalry is moved right forming a continuous line against the Union infantry while a division from Longstreet is placed in position to attack. CAS units are ordered not to break the line or advance after attacking.

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CAS makes a limited attack designed to test the Union and inflict as many casualties as possible. Actual losses are about even, however, the Union troops retreat from the engagement and should be temporarily out of position for their next round of attacks.

[Cpl GAC]

Having biked the battlefield - Burnside Bridge is surprisingly small and narrow.

[rhinobones]

Having biked the battlefield - Burnside Bridge is surprisingly small and narrow.

You have a perspective few of us share. Nice bike ride!
With a width of only 12 feet, defending the crossing against an overwhelming Union force becomes easier to comprehend.

Regards

[rhinobones]

Turn 2 Union

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Union forces resume the attack against Jackson’s divisions defending the CAS left flank. This time they launch a series of attacks at two locations but Jackson’s troops hold firm.

Some Union movements are detected to the East, but so far Union strength or location is unknown.

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T2 – Union Battle Results 4_6.jpg (196.5 KiB) Viewed 1469 times

Two Union divisions launch four assaults (1, 3, 5, 6) against Jackson (J.R. Jones division) with Jackson holding and getting a bit better of the battle. After the sustained combat Jackson’s troops are low on supply but not yet critical.
A single Union division attacks twice (2, 4) toward Longstreet (J.B. Hood) with mixed results. Casualties are even and Longstreet keeps the position.

[rhinobones]

Turn 2 - CSA

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Union activity along the left (northern) flank appears to need immediate attention; units stationed in Sharpsburg are redeployed to the North. Two artillery units from Lee’s Reserves are transferred, one moves North to support the left flank and one moves to support the center near the Sunken Lane. A division of Longstreet’s (McLaws) also moves out of Sharpsburg and joins another Longstreet division (Hood) in the center.

These redeployments strengthen the left and center, but there is a concern that the right (southern) flank may be undermanned. Since the Union has not formed for an attack on the right the CAS feels that there is no imminent danger. On the left the opportunity exists to get superiority in numbers and push back the Union.

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A division from Lee’s Reserve (Anderson) and artillery (Pendleton) join with Stuart’s cavalry to assault a lone Union division. In spite of having more rifles and guns the CSA is disappointed with the results. The Union mostly loses some horse teams and then withdraws, but otherwise little damage is done.

[rhinobones]

Turn 3 - Union

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Union forces are on the move. Three divisions join the center line taking up positions for assaults on the rebels. The troops have arrived tired from their forced march and will require a short rest before continuing the attack.

So far, no Union formations have arrived on the far southern flank. The focus of the Union attack appears to be on the CSA’s center and left flank.

[rhinobones]

Turn 3 - CSA

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Lee shifts Stuart’s cavalry from the left flank to the center; this gives Lee four divisions plus artillery against one Union division. The rebels assault using limited tactics. The intention is to drive the Union division back and prevent a concentrated Union attack toward Sharpsburg.

For the moment the left and right flanks are not being pressured and are thought to be secure using the forces already in place.

T3 – CSA Battle Results.jpg (121.26 KiB) Viewed 1396 times

Even though the Union division’s rifle companies are more numerous and outnumber the CSA, the rebels are able to gain about a two to one kill ratio. The Federals however are able to hold their ground in spite of the casualties. The rebels consider their attack successful and break off the engagement to secure a defensive position.

[rhinobones]

Turn 4 - Union

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Six Union divisions make concentrated assaults against the rebel center. Four divisions attack the McLaws/Hood position and two attack Jackson’s division commanded by J.R. Jones. Casualties are high on both sides, but the CSA manage to hold their line.

On the CSA left flank the Union forces hold their positions and appear to be replenishing for the next attack.

No Union forces have been observed on th right flank. This gives the rebels time to adjust the available troops for the best defensive positions.

T4 – Union Battle Results Jones.jpg (189.41 KiB) Viewed 1365 times

Union formations make two assaults against Jone’s division with terrible results. The Union loses 21 infantry companies to one rebel company. The Union breaks off the engagement and attempts to reform the decimated divisions.

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Union divisions attack the McLaws/Hood position from three sides with multiple assaults. Casualties are heavy; rebels lose 14 infantry companies and 7 guns while the Union loses 15 infantry companies. The division of McLaws stands firm and covers the withdrawal of Hood’s division.

[rhinobones]

Turn 4 - CSA

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As a result of the Union attacks on the center, McLaws division was left in a position surrounded on four sides by superior numbers. Lee finds it prudent to pull McLaws back, shorten the rebel line, form up with Hood and Stuart’s divisions and replenish. McLaws and Hood’s divisions currently have minimal supply.

On the left flank the rebels are able to bring two divisions (Jackson’s Hill and Lee’s Anderson) with artillery support against an unsupported Union division. The attack goes poorly, and the rebels fall back to prepare for the Union retaliation.

T4 – CSA Battle Results.jpg (93.84 KiB) Viewed 1353 times

The rebels attacked with almost a four to one advantage but were repelled with losses of four infantry companies to two Union companies. Even though the casualties represent a small portion of the total CSA strength, losing twice as many troops as the enemy damages both confidence and morale.

[rhinobones]

Turn 5 - Union

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In the center Lee’s Reserve artillery (H.P. Jones) and Jackson’s division (R.J. Jones) are attacked by three Union divisions. The attack is a single assault after which the Union divisions break off the engagement. Total casualties are light on both sides.

The Union continues the battle with attacks on the left flank. On the left two Union divisions, having superior infantry and artillery numbers, assaults Lee’s Reserve (Anderson). The Union infantry is in the open and Anderson is defending from the forest which enables the rebels to repulse the Union. After multiple tries all attacks are repulsed with the CSA sustaining 5 infantry company casualties and the Union 10.

Burnside’s Corps makes its appearance along the southern (right) flank. The Union will attempt to cross a stone bridge which will later be renamed as “Burnside Bridge”. The Union will pay for the naming rights as the rebels are defending a river crossing and have the added advantage of high ground.

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T5 – Union Battle Results (Attacks 2 thru 4).jpg (192.65 KiB) Viewed 1327 times

The heaviest Union casualties are sustained in the assaults against the rebel left flank. Anderson’s division has the defensive benefit of a wooded position which the Union is unable to overcome. The Union still maintains superior numbers, so more assaults are expected.

[rhinobones]

Turn 5 - CSA

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The rebels survey the battlefield and decide that the left flank is the most vulnerable. To bolster their defense Stuart’s cavalry and a division of Jackson (D.H. Hill) are shifted to the left. These two units have good supply while most of the other divisions defending the center and left are severely undersupplied. They are ordered to remain static and regain as much resupply as possible.

Longstreet’s division (Jones) and artillery defending against Burnside are at full strength and supply. They have the difficult task of holding off all Union attempts to capture Sharpsburg from the South.

The rebels do not initiate any attacks during this period.

[rhinobones]

Turn 6 - Union

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Union forces focus their attention on the Confederate center. Divisions of Summer’s Corps, supported by a division of Manfield, assault Jackson’s division (J.R. Jones). The attack forces Jones, along with Lee’s artillery, to withdraw from the center. A division of Summer advances into the vacated position.

With the CAS center pushed back, it becomes possible for the corps of Summer and Manfield to make an advance toward Sharpsburg. The success of this attack has put the rebels in a precarious tactical position.

The northern and southern flanks are unexpectedly quiet. The northern divisions may be recovering from recent fighting, so their inactivity is understandable. But it is not obvious why Burnside has not tried to force the river crossing.

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The Union assault is successful however, they sustain twice the casualties of the CSA. Even though the rebels were positioned on the high ground, the Union had better than 12 to 1 infantry advantage and should have been able to do more damage. The Union took the bluff but are now required to hold using a wounded division.

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Halfway through the engagement the Union has infantry casualties of just over 10% killed and wounded. It appears that the infantry are either insufficiently trained or the tactics employed are faulty. Maybe some of both reasons. Artillery losses are very low. Conclusion; it’s good to be in the artillery.

[rhinobones]

Turn 6 - CSA

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The rebels know that the advancing Union division has sustained significant casualties and attempts to capitalize on its weakness. The Confederates form an attack composed of Stuart’s cavalry and Longstreet’s divisions (Hood and McLaws) with Lee’s artillery in support.

Movement of Stuart’s cavalry leaves two strong and one weakened division guarding the northern left flank. Artillery support is available for all three divisions.

T6 – CSA Battle Results.jpg (110.15 KiB) Viewed 1242 times

The Union division was weaker in artillery but total infantry companies was about equal. The rebels were able to gain a minor win while inflicting minimal Union casualties. This assault exhausted the supply carried by Longstreet’s infantry causing further attacks to be called off.

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CSA losses (infantry + cavalry = 31) are running at about half of the Union losses (infantry = 63). This probably reflects that the Union is the aggressor and CSA is primarily playing defense. Even with the losses the Union does have a clear path to Sharpsburg by pushing through the CAS center and/or releasing Burnside in the South. CAS is having difficulty defending the center and both flanks simultaneously.

[rhinobones]

Turn 7 - Union

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The Union commander unleashes Burnside who immediately attacks across river with disastrous results. Burnside assaults in three waves, each of which is severely beaten back. The rebels make perfect use of their high ground and river defense.

In the center Summer’s Corps attacks two divisions of Longstreet and has equally poor results. Summer is smart enough to stop the engagement after one assault.

T7 – Union Battle Results (2).jpg (105.32 KiB) Viewed 1201 times

The center attack by Summer is also costly. Summer’s Corps sustains infantry casualties of 8 companies as compared to CSA loss of 3 companies. This engagement is notable in that it is one of the few where the rebels had superior numbers of artillery support.

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Burnside’s attack cost the Union 17 infantry companies as opposed to only 3 for the Confederates. This loss severely impacts the fighting ability of Burnsides Corps.

[rhinobones]

Turn 7 - CSA

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The rebels take the opportunity to replenish supplies. Quite a few units are down to 10% – 30% supply (red and orange) while one of Jackson’s divisions is still in reorganization. Considering the casualties the Union sustained during their last round of attacks, the intensity of the Union aggression may take a while to recover.

[rhinobones]

Turn 8 - Union

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The Union army does not take a turn to rest and replenish but instead fiercely attacks by driving Burnside’s Corps across Antietam Creek and moving toward Sharpsburg. Burnside advances after four waves of assaults which positions his Corps on the town outskirts.

In the center Summer’s Corps makes another assault on Longstreet’s division but has little effect. The rebels hold their position inflicting a few more casualties than received.

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Summer’s Corps attack (2) against Longstreet results in the loss of three Union and two CSA infantry companies. The loses are insignificant and only show that the rebels are able to repel attacks by Union infantry having superior numbers.

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Burnside makes three assaults (1,3,4) against Jackson’s division (D.R. Jones) and artillery before successfully crossing Antietam Creek bridge. This bridge will later be named after Burnside and the soldiers who fought there. Net casualties are Union 9 companies, rebels 8 companies. Considering the rebels were outnumbered almost 3 to 1 total CSA casualties are fairly light.
After the crossing a division of Burnside (Wilcox) is able to make an additional attack (5) pushing Jackson further toward Sharpsburg. Casualties are light; however, Longstreet’s division now requires reorganization before continuing offensive operations.