Jordan begins by examining the reasons for Robert E. Lee’s invasion of Maryland in the aftermath of his victory at Second Manassas.  Aside from being part of the Confederacy’s only multi-front strategic offensive of the war, Jordan suggests that Lee’s ultimate aim was to take the Army of Northern Virginia into Pennsylvania.  This would serve to perhaps influence the upcoming 1862 elections.  Jordan’s treatment of the evidence here is very careful, and his argument is well presented and convincing.

The idea of Pennsylvania as Lee’s objective also serves to highlight the importance of South Mountain.  By pushing the Army of the Potomac through the South Mountain passes, newly re-appointed commander George McClellan, informed of Lee’s dispositions by the capture of Special Order Nr. 191, effectively cut off Lee’s route north.  It also served to force Lee to fight, if he wished to, with his back to a major river.  Lee decided to do just that, a decision even his most admiring supporters called foolish in the extreme.

Jordan goes into a well-organized and detailed treatment of the battle, covering the actions at Fox’s, Turner’s, and Crampton’s Gaps in that order.  The approach taken by Jordan here can get a bit into the weeds, but that is probably unavoidable to some degree.  Jordan adds a chapter at the end on how Union and Confederate veterans and authors looked at South Mountain and its importance after the war.  The book also has an excellent set of maps and a number of photographs, not just of the major commanders, but also period and modern photos of the key parts of the battlefield.

This study holds much for both the serious scholar and for the novice.  Jordan’s book will stand as the most authoritative study of South Mountain for some time to come.