 There was only one potential weakness in Lee's line—the exposed salient known as the "Mule Shoe" extending more than a mile (1.6 km) in front of the main trench line.Although Lee's engineers were aware of this problem, they extended the line to incorporate some minor high ground to Anderson's right, knowing that they would be at a disadvantage if the Union occupied it.The Union soldiers were also busy building their own entrenchments.