As part of that siege, units under Maj. Gen. Lafayette McLaws were sent to take Maryland Heights and then bombard the Union garrison in the town. To protect his rear flank, McLaws stationed a small guard at Brownsville Gap (a smaller gap a few miles south of Crampton's Gap) and Crampton's Gap, both of which allowed access to Pleasant Valley and the eastern slope of Maryland Heights. The force at Crampton's Gap consisted of one battery of artillery, three regiments of infantry under Brig. Gen. William Mahone, one brigade under Brig. Gen. Howell Cobb, and a small cavalry detachment under Col. Thomas T. Munford. After the report of a very large number of camp fires indicating a much larger Union force than anticipated, General Lee recognized the threat this posed to his split forces, so the order was sent down to General Cobb to ..."hold the gap if it cost the life of every man in my command".