In July 1861, this treeless hilltop offered an excellent view of the surrounding country, allowing Capt. Edward P. Alexander to establish a Confederate signal station here and send wigwag messages to other positions without a tower. As Union Gen. Irvin McDowell's army approached, the Centerville station was abandoned, but Alexander's men continued to pass vital intelligence along the Confederate line. On the morning of July 21, 1861, while watching the Van Pelt signal station during a Union diversionary attack at the Stone Bridge seven miles northwest, Alexander noticed the glint of a brass field-piece, then bayonets and musket barrels, revealing a large Union column marching toward Sudley Springs to turn the Confederate left flank. He immediately warned Col. Nathan G. Evans at the Stone Bridge, "Look out for your left, you are turned." This was the first combat use of the wigwag system, and the warning enabled Evans to intercept the Union flanking column, gain time for Confederate reinforcements, and contribute significantly to the Confederate victory at First Manassas.
