onsboro turnpike enters the village
from the northeast, crossing the Antietam on a stone bridge, and
continuing through Sharpsburg to the southwest, reaches
Shepherdstown by the ford of the Potomac already mentioned. The
Hagerstown turnpike enters the town from the north, passing the
Dunker Church a mile out, and goes nearly due south, crossing the
Antietam at its mouth, and continuing down the Potomac toward
Harper's Ferry.

The Antietam is a deep creek, with few fords at an ordinary stage of
water, and the principal roads cross it upon stone bridges. Of these
there were three within the field of battle; the upper one in front
of Keedysville, the middle one upon the Boonsboro turnpike, and the
lower one on the Sharpsburg and Rohrersville road, since known as
Burnside's bridge. McClellan's staff was better supplied with
officers of engineers than the staff of most of our separate armies,
and Captain Duane, his chief engineer, systematized the work of
gathering topographical information. This was communicated to the
general officers in connection with the orders which were given
them. In this way we were instructed that the only fords of the
Antietam passable at that time were one between the two upper
bridges named, and another about half a mile below Burnside's
bridge, in a deep bend of the stream. We found, however, during the
engagement of the 17th, another practicable crossing for infantry a
short distance above the bridge. This was not a ford in common use,
but in the low stage of water at the time it was made available for
a small force.

It was about noon of the 15th of September that Lee placed the
forces which he had in hand across the turnpike in front of
Sharpsburg. D. H. Hill's division was on the north of the road, and
on the south of it Longstreet's own old division (now under General
D. R. Jones), Hood's division, and Evans's independent brigade.
Stuart's cavalry and the reserve artillery were also present. The
rest of the army was with Jackson at Harper's Ferry, or co-operating
with him in the neighborhood of Maryland Heights. Out of forty-four
brigades, Lee could put but fourteen or fifteen in line that day to
oppose McClellan. He was very strong in artillery, however, and his
cannon looked grimly over the hill-crests behind which his infantry
were lying. Cutts's and Jones's battalions of the reserve artillery
were ordered to report to Hill for the protection of the left of the
Confederate line, and