It is not uncommon in war for a mistake to have consequences far greater than might have been expected at the time.  Also, for these consequences to occur it requires that the other side take advantage of the mistake.  Both were to happen on the morning of the 20th September.

Map from 11:00 till early afternoon Kellogg rides to Rosecrans Ambiguity in the order to Wood Diagram of Wood’s move Wood’s view of his need to obey Map showing Wood’s move Rosecrans’ report of the move

While writing this section I was minded of some of the events behind the Charge of The Light Brigade, and have added a page outlining some of those views.

The map below shows the action a little before mid-day, and into the afternoon.

Whilst the attacks by Polk’s units on Thomas had not succeeded, they had caused Thomas concern, he believed he needed still further reinforcement, and sent staff officers out with that request.  One of those officers was Captain Kellogg, who reached Brannan’s division around 10am., Brannan, after consulting with Reynolds, would go to assist Thomas.  Brannan was in the line near the Poe field, between Reynold’s division to the north of him, and Wood to the south. If Brannan were to leave the line to join Thomas then these other two divisions would be left with their flanks exposed, it would be necessary for someone to ‘plug the gap’.  While Brannan’s reserve brigade had left to join Thomas, and before the remainder moved off, Kellogg was dispatched to Rosecrans to ensure that he was aware of the need to fill the gap that would be left.

Kellogg rode towards Rosecrans along the Glenn-Kelly Road, which passed behind Reynolds and Brannan, whose forces were in the forest and scrub to the east of the road.  As Kellogg rode along he became convinced, because he could not see Brannan through the forest, that Brannan had gone, that there was a gap in the line, and that Reynolds right flank was in the air.  His message to Rosecrans was “Brannan was out of the line and Reynold’s flank was exposed”.  Rosecrans, assuming that Brannan had left the field, based on Kellogg’s report, had Major Frank Bond write an instruction to Wood at 10:45 “The General Commanding directs that you close up on Reynolds as fast as possible, and support him”.

Brigadier General Garfield, as Rosecrans’ Chief of Staff, ordinarily wrote the orders to Rosecrans’ commanders, and his use of english was generaly considered such as to leave no room for misunderstanding.  In this one instance he did not write the order, and order which was not clear and which was to have such dire consequences for the Federals in the rest of the battle.

Wood’s line ran through some trees in front of the Glenn-Kelly Road, to the west of the Brotherton House, with Brannan to his left.  To Wood, receiving the order, the instruction from Rosecrans was confusing.  Although Rosecrans had issued the order assuming that Brannan had left the line, Wood knew that he had not.  Brannan was still between Woo and Reynolds.  In this situation, and in the militart parlance of the time, the order required two mutually exclusive manoeuvres.

Photos showing the Brotherton cabin, and the view from the cabin to the woods to the west of the Brotherton field.  Photos J Dillon, Sept. 2002.

The order to “close up on” required Wood to move to his left, adjacent to Reynolds and still in the line with him.  The order to “support” required him to take up a position out of the line, behind Reynolds. Because Brannan was still in position, though ready to move, he could not move adjacent to Reynolds, i.e. “close up on”, so he would have to leave the line and pass behind Brannan to move to a position behind Reynolds where he could “support” him. McCook had been present when Wood received the order and persuaded Wood that Rosecrans must necessarily have a better overall view of the situation, that Wood should move in “support” and he, McCook, would move some of his units in to replace Wood. This convinced, Wood moved. There would later be much discussion and debate on whether or not Wood should have moved, but given his previous “dressing down”, there is no wonder that he followed Rosecrans’ direct order this time.

On the previous page, “Attack Starts”, Negley was to move out of the line to go to the support of Thomas, and McCook was ordered by Rosecrans to fill the gap left by Negley; “General Negley’s division has been ordered to General Thomas’ left. The general commanding directs you to fill the space left vacant by his removal, if practicable. The enemy appears to be moving toward our left.” [order from Rosecrans]

From McCook’s post-battle report; “Immediately upon receipt of this order, Major-General Sheridan and myself rode to the position vacated by General Negley’s divisio.  We found nearly all this space already occupied by General Wood’s division. He informed me that his left rested on General Brannan’s right, and that his orders were to close up on General Brannan.”

McCook was then ordered “to send two brigades of General Sheridan’s division at once and with all possible dispatch to support General Thomas....”  Then, from McCook’s report again; “The order was executed at once. Two bigades of Sheridan’s division, Lytle’s and Walworth’s, were taken from the extreme right, and were moving at the double-quick to the support of General Thomas. Simultaneously with this movement, and much to my surprise, Wood’s division left the position it held in line of battle on Davis’ left, marching by the left flank, leaving a wide gap in the line of battle.”

Wood’s move behind Brannan to “support” Reynolds.

Palmer said of the order “Wood was merely unfortunate; he had attempted to obey an order dictated by ignorance of the situation”. The order could also be assumed by Wood to have unusual urgency as it came direct to him from the Commanding General, not via his corps commander, Crittenden. However, even though Wood had received a “dressing down”, and could be sympathised with for not wanting another, he knew the order was not logical, and he knew he had the enemy to his front, so he also knew the consequences of trying to comply.  He should have asked for clarification in the circumstances. 

Wood’s view of his position was described in his statement in the Official Record.

“The order was not only mandatory, but peremptorily mandatory. It directed me to close upon General Reynolds, a movement of one body from the rear to another body in front of it. But is gave me the reason for the movement - viz., to support the body of troops in front - the most important reason that can exist on the field of battle.

With this order in my hand, with Brannan on my left, with no knowledge of Reynold’s position, but with a peremptory order to close up on him and support him, it was physically impossible to obey it in any other way than I did - viz., by withdrawing from the line, passing to the left, finding Reynolds’ position, closing up on him, and supporting him”.

The map above (again from the alabama map archive) shows the Brotherton and Dyer Farms in green, Wood is moving away north leaving the gap in the line below these two farms.

Wood, possibly because of his earlier ‘dressing down’ had forgotten that on December 29 at Murfreesboro Rosecrans had shown him that he did not expect one of his commanders to blindly obey an order that he knew to be based on incorrect facts. Wood knew there was no gap to his left, the important fact on which Rosecrans had based the order.

From Rosecrans’ post battle report

An aide arriving from General Thomas, requesting that Negley's remaining brigades be sent forward as speedily as possible to succor the left, General Crittenden was ordered to move Van Cleve, with all possible dispatch, to a position in the rear of Wood, who closed in on Brannan's right. General McCook was ordered to move Davis up to close in on Wood, and fill an opening in the line.

On my return from an examination of the ground in the rear of our left center, I found to my surprise that General Van Cleve was posted in line of battle on a high ridge much too far to the rear to give immediate support to the main line of battle, and General Davis in line of battle in rear of the ridge occupied by Negley's reserve in the morning. General Crittenden was ordered to move Van Cleve at once down the hill to a better position, and General Davis was also ordered to close up the support of the line near Wood's right.

The battle, in the meanwhile, roared with increasing fury, and approached from the left to the center. Two aides arrived successively within a few minutes, from General Thomas, asking for re-enforcements. The first was directed to say that General Negley had already gone and should be near at hand at that time, and that Brannan's reserve brigade was available. The other was directed to say that General Van Cleve would at once be sent to his assistance, which was accordingly done.

A message from General Thomas soon followed, that he was heavily pressed, Captain Kellogg, aide-de-camp, the bearer, informing me at the same time that General Brannan was out of line, and General Reynolds' right was exposed. Orders were dispatched to General Wood to close up on Reynolds, and word was sent to General Thomas that he should be supported, even if it took away the whole corps of Crittenden and McCook.

General Davis was ordered to close on General Wood, and General McCook was advised of the state of affairs and ordered to close his whole command to the left with all dispatch.

General Wood, overlooking the direction to" close up "on General Reynolds, supposed he was to support him, by withdrawing from the line and passing to the rear of General Brannan, who, it appears, was not out of line, but was en échelon, and slightly in rear of Reynolds' right. By this unfortunate mistake a gap was opened in the line of battle, of which the enemy took instant advantage, and striking Davis in flank and rear, as well as in front, threw his whole division in confusion.

The result of the order to Wood, and his attempt to follow the instruction led to a gap in the line, a gap which was exploited by the Confederate General, Longstreet.