For a body of troops to charge up Marye's Heights, bristling as they did with hostile and well served cannon, and defended by tens of thousands of veteran riflemen, was a task that might well have appalled even such sturdy fighters as composed the Army of the Potomac. But the matter was made more difficult by another peculiarity of the ground. Looked at from below, the hill seemed to present a smooth surface, ascending gently toward the works that defended it. But this appearance was deceptive. On the side of the hill well in advance of Lee's main line, and running athwart the Federal line of advance, there was a sunken road, faced with a stone wall, which formed as perfect a breastwork as any that an engineer could have constructed there. Into this sunken road Lee threw about two thousand riflemen, who lay there perfectly concealed from view and as well protected against adverse fire as men using rifles can be. Their orders were to withhold their fire until the enemy charging up the slope under a destructive cannonade from above, and thinking of the works at the top as the first obstacle to be encountered, should reach a point a score or so of yards in front of the sunken road, whence they could be swept away like dust before a housemaid's broom. It was as deadly a trap as could be imagined, and its concealment was perfect. Yet when the Federal general decided to make his main attack upon Lee's left, there was no course open to him but to take this doubly defended hill by assault or suffer fearful disaster, as he did, in a futile attempt to do so. For the nature of the ground on Lee's farther left rendered it impossible to turn his flank or try conclusions with him otherwise than by a direct charge upon Marye's Heights. The first attack was made by French's division. It was already suffering terribly under the fire from the hilltop, when it came upon the sunken road and was instantly swept away by a hailstorm of bullets. Retiring, French left about one half of his men on the field, dead or wounded. Hancock charged next with five thousand men and was driven back with a loss of two thousand or more. The exact nature of the case was not even yet understood. The position in the sunken road was still masked to the Federal commanders. But French's and Hancock's attempts had conclusively shown that no courage, no determination, no heroism however high, could enable mortal men to carry that hill by assault. Nevertheless Burnside persisted where a wiser leader would either have withdrawn or have changed his plan of battle. He sent another, and another, and still another division into that fire of hell, only to see them instantly hurled back, shattered fragments of most gallant commands, beaten, broken and well-nigh destroyed by reason of a blundering obstinacy on the part of their commanding general.