USS Sophronia (1861)

Assigned to Comdr. David Porter's Mortar Flotilla, the schooner sailed for Key West, Florida, where the other ships of the force assembled before moving on to Ship Island, Mississippi, on 6 March. On the 18th, the mortar boats were towed across the bar at Pass a L'Outre into the Mississippi River. A month later, the flotilla moved upstream to positions below Forts Jackson and St. Philip and opened fire.

Sophronia anchored some 3,000 yards from Fort Jackson and began lobbing mortar shells into the fort, at 1000, at the rate of six an hour. The bombardment continued intermittently until Admiral David Farragut had safely dashed past Forts Jackson and St. Philip on the morning of the 24th. New Orleans, Louisiana, fell to Admiral Farragut the next day, and the two forts surrendered on 28 April as they were cut off from their source of supplies and Union forces were prepared to attack them from three sides.

Early in May, Porter took his Mortar Flotilla back to the Gulf of Mexico, but they were recalled to the Mississippi River and ascended the river in June to support Farragut's operations against Vicksburg.

However, General Robert E. Lee's successful Seven Days campaign prompted the U.S. Navy Department to recall some of Porter's schooners for possible service on the James River to help protect General George McClellan's beleaguered army.

Sophronia arrived in Hampton Roads, Virginia, on 31 July and thereafter operated in Chesapeake Bay and on the rivers of Virginia.

Sophronia was attached to the Potomac Flotilla in early 1863 and was assigned duty as a guard ship at Piney Point, Virginia. On 19 May, she captured the schooner Mignonette which was carrying contraband. In June 1864, she was one of four schooners assigned to aid a Union Army expedition up the Rappahannock River, after which she resumed her post at Piney Point.