Robert E Lee’s artillery commander, E P Alexander, wrote a book about the war and did not flinch when it came time to have opinions on fellow commanders in various battles. Here he writes about Lee’s choice of defense at Sharpsburg.
‘Whatever the advantages or disadvantages of the field, there was one feature of it which should have been conclusive against giving battle there. That feature was the Potomac River. We were backed up against it, within two miles, and there was no bridge and but a single ford accessible, and that a bad one, rocky and deep. On the Maryland side, a mile of hilltops, some of them beyond the Antietam, offered sites for rifled guns to rake the ford and entirely cut off any retreat, should we meet with a reverse. This single feature of the field should have been conclusive against giving battle there. I believe that Lee would never have done so, had he ever before crossed the ford in person. Briefly, the most sanguine hope which Lee could reasonably entertain, with his inferior force, was to fight a drawn battle, and then safely withdraw what was left of his army. Against it he risked its utter destruction, which would have been the speedy end of the Confederacy’.
John Codman Ropes (see below), the best critic and the best-informed writer upon the war, comments as follows upon the situation at this time. ‘This decision, to stand and fight at Sharpsburg, which Gen. Lee took on the evening of Sept. 14, just after his troops had been driven from the South Mountain passes, is, beyond controversy, one of the boldest and most hazardous decisions in his whole military career. In truth, it is so bold and so hazardous that one is bewildered that he should even have thought seriously of making it. Nearly the whole force which he had on the north bank of the Potomac had been engaged that afternoon, in an unsuccessful attempt to hold a defensive position, and it had been badly beaten. . . . Of his two principal lieutenants, one, Longstreet, was opposed to this perilous course. Jackson, however, was, as we know, in favor of making a stand at Sharpsburg.’
Alexander, Edward Porter- Military Memoirs of a Confederate: A Critical Narrative
John Codman Ropes (1836–1899) was an American military historian. His principal work is an unfinished Story of the Civil War, to which he devoted most of his later years; this covers the years 1861-62. The Army under Pope is a detailed narration of the Virginia campaign of August-September 1862, which played a great part in reversing contemporary judgment on the events of those operations, notably as regards the unjustly-condemned General Fitz John Porter. Outside America, Ropes is known chiefly as the author of The Campaign of Waterloo, which is one of the standard works on the subject