On either side were deep chasms or mountain walls.

A direct attack along the road was an impossibility.

A flank movement seemed equally impossible.

After the arrival of the commanding-general upon the scene, reconnoissances were sent out to find, or to make, a road by which the rear of the enemy's works might be reached without a front attack.

These reconnoissances were made under the supervision of Captain Robert E.Lee, assisted by Lieutenants P.G.
T.Beauregard, Isaac I.Stevens, Z.B.Tower, G.W.Smith, George B.
McClellan, and J.G.Foster, of the corps of engineers, all officers who attained rank and fame, on one side or the other, in the great conflict for the preservation of the unity of the nation.