the destructive foray of the confederate ironclad ram "albemarle" from the roanoke river into albemarle sound, north carolina, on 17 april and her reappearance on 5 may—the day grant's offensives began—increased union anxiety over the possibility that the confederate squadron at richmond might descend the james, wrest control of that vital stream from the union flotilla, and wreck butler's transports and supply ships, stranding his troops in hostile territory where they would be at the mercy of southern soldiers. to prevent such an eventuality, welles sent several warships, formerly ordered to the gulf of mexico, to hampton roads, virginia, to reinforce the james river flotilla.