He fought at the First Battle of Bull Run, afterward was engaged until 1862 upon the defenses of Washington, D.C.. He then commanded the Engineer Brigade during the Peninsula Campaign and the Northern Virginia Campaign, as well as during the Battle of Antietam.
He participated in the First Battle of Bull Run, subsequently defending Washington D.C. until 1862. He later commanded the Engineer Brigade during the Peninsula Campaign and Northern Virginia Campaign, as well as the Battle of Antietam.