American Military History, Volume 1

Near Cerro Gordo, the national highway ran through a rocky defile. On the left of the approaching Americans, Santa Anna with about 12,000 men had emplaced batteries on mountain spurs; and on the right of the Americans, farther down the road, his guns were emplaced on a high hill, El Telegrafo. He thus had firm command of the national highway, the only means he thought Scott had of bringing up his artillery.

Fortunately for Twiggs, advancing on the morning of April 12, the Mexican gunners opened fire before he was within range and he was able to pull his forces back. Two days later Scott arrived with reinforcements, bringing his army up to 8,500. A reconnaissance by Captain Lee showed that the rough country to the right of El Telegrafo, which Santa Anna had considered impassable, could be traversed to enable the Americans to cut in on the Mexican rear. The troops hewed a path through forest and brush; when they came to ravines, they lowered the heavy siege artillery by ropes to the bottom then hoisted it up the other side. By April 17 they were able to occupy a hill to the right of El Telegrafo, where they sited the rocket battery. Early on the morning of April 18 the battle began.