If Wood remains in position what happens?
At some point Longstreet's weight of numbers would have likely pushed Wood's force back to the Dyer defensive line. With this visible threat to his right flank Rosecrans would have kept some men in that vicinity. It is logical to believe that once the size of Longstreet's attack had been known Rosecrans would have suspended the movement orders for Major General Philip Sheridan and Brigadier General Horatio Van Cleve's divisions and retained them in that area. This would have left Rosecrans with Crittenden's artillery, Colonel John T. Wilder's brigade and Brigadier General Jefferson C. Davis, Wood, Sheridan, and Van Cleve's divisions to defend his right flank in the Dyer Ridge area. Major General Gordon Granger had Brigadier General James Steedman's two brigade division of the Reserve Corps in motion at about 1:30 PM and arrived at Snodgrass Ridge around 2:30 or 3 PM. If he had been needed at Dyer Ridge he could have been brought there soon after his arrival at Snodgrass Ridge, certainly by 3:30 P.M.
Dyer Ridge, overlooking the flat ground to the east, offers open fields of fire and a fair amount of elevation change. The distances from the Glenn-Kelly Road (which is the approximate tree line) to the defensive positions along Dyer Ridge range from 300 yards at the southern flank at Lytle Hill to 500 yards where the Union artillery was placed overlooking Dyer Field. The northern extremity of Dyer Field (where the South Carolina monument is now) is a little over 300 yards from the road. The Dyer House is also about that far from the road, while Rosecrans' headquarters is over 600 yards from the road. The elevation differences from the road to the defensive line are pretty steady at about 70 feet higher. The northern extremity of Dyer Ridge is 75 feet higher than the road, at the artillery line it is 70 feet and at Lytle Hill it is 60 feet. The Dyer house is about the same elevation as the road and Rosecrans' headquarters is about 35 feet higher. While not significant distances or heights they would offer some help to the defenders.
According to Hardee’s Rifle and Light Infantry Tactics, the standard training manual for Civil War soldiers, the common march time was 90 steps a minute with a 28 inch stride and double quick as 165 steps a minute with a 33 inch stride. That means to cover the 300-500 yards from the road to the top of the ridge the attackers would have been under fire for 2-3 minutes of quick time or 4-7 minutes at common march. Assuming that an artillery piece could fire about 2 rounds a minute the attacking Confederates would have been subjected to approximately 4-14 rounds of canister from each gun. The supporting Union infantry would also have fired roughly the same number of volleys, perhaps a few more. The parts of the ridge that were closer to 500 yards away from the tree line would be able to fire a significant amount of canister and musketry. Other portions of the defenses would not be able to fire as much; but if Wood had previously battered Longstreet’s column, this fire might have been enough to stop that attack. Future Confederate attacks would also probably have very little artillery support as the nearby tree line would prevent them from moving much up close. It is possible that the Confederates could have put artillery in Brotherton Field and fired from that position against Dyer Ridge but, at least initially, there would have been a tree line that would have interfered with that fire.
Tour Update 2/4/2016
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