Served on board the USS Pensacola in the attack on Forts Jackson and St. Philip and at the taking of new Orleans, 24 and 25 April 1862. Swept from the bridge by a shell which wounded the signal quartermaster, Flood returned to the bridge after assisting the wounded man below and taking over his duties, “Performed them with coolness, exactitude and the fidelity of a veteran seaman. His intelligence and character cannot be spoken of too warmly.”