Complex sentence: They stopped and hid at a position on the Mechanicsville turnpike just behind the crest of the commanding hill and waited there for Maj. Gen. A. P. Hill to attack the other side of Mechanicsville.
Split into simpler sentences: They stopped and hid at a position on the Mechanicsville turnpike just behind the crest of the commanding hill. They waited here for Major General A. P. Hill to attack the other side of Mechanicsville.