|Capt. James Chatham Duane (courtesy|
of the United States Lighthouse Society)
The situation on the northern end of the Federal line did not present as much of an issue as the state of affairs in the sector of the Ninth Corps when it came to crossing the Antietam. There, Confederate forces positioned themselves overlooking the creek and a major bridge crossing (the Lower, or Burnside, Bridge). In fact, some of the Confederate skirmishers held a foothold on the creek's eastern bank, making any Federal reconnaissance surveying the approaches to the bridge or additional crossing points incredibly difficult. Despite those circumstances, McClellan looked to Duane and his engineers to survey the creek on the battlefield's southern end.