The Battle of South Mountain casualties total 2,346 soldiers, out 28,000 who fought for the Union, while the Confederates lost 3,434 out of 18,000 soldiers.
The Battle of South Mountain is also known as Battle of Boonsboro Gap in some Southern accounts. It happened on September 14, 1862 during the American Civil War as part of Maryland Campaign. The battle consists of fighting for possession of three South Mountain passes, namely Crampton's, Turner's, and Fox's Gaps. General George B. McClellan, commanded the Union Army of the Potomac to pass through these gaps to pursue Confederate General Robert E. Lee's dangerously divided Northern Virginia Army.
A Confederate squadron and a small portion of Maj. Gen. Lafayette McLaws's troops defended Brownsville Pass and Crampton's Gap. Maj. Gen. Henry Warner Slocum attacked on the right and Maj. Gen. William F. “Baldy” Smith charged on the left, winning the battle to claim the gap. They captured 400 prisoners, mostly from Brig. Gen. Howell Cobb's brigade, who came late. Confederate Maj. Gen. D. H. Hill guarded both Turner's Gap and Fox's Gap.
Battle of South Mountain Casualties & Crampton's Gap (September 14, 1862) (Lee not present)
|Current, Encyclopedia||387 killed|
|Eicher, Longest Night||325 killed|
|Fox, Regimental Losses||438 killed|
|Gallagher, Civil War (South Mtn. Only)||2,700*||2,300*|
|Phisterer, Statistics||4,343*||443 killed|
|Author's Best Estimate:||3,434*||2,346*|