De Soto's speed made her an effective pursuit ship, and she would capture or bring about the destruction of a total of eighteen blockade runners during the war.

In the postwar period, De Soto continued to serve with the Navy, mostly in South American waters, until resold to her original owners in 1868 for resumption of service as a passenger ship.

[4] De Soto was powered by a 65-inch (170 cm) bore, 11-foot (3.4 m) stroke single-cylinder vertical beam engine,[5] built by the Morgan Iron Works of New York.

[3][5] The engine, which drove a pair of 30-foot[5] sidewheels,[3][4] was capable of delivering up to 14 mph (12 knots)—a good speed for the time, which would soon make De Soto a favorite with the travelling public and which would later prove invaluable for pursuing blockade runners during the Civil War.

[6] De Soto appears to have entered service in August 1859,[7] carrying mail, passengers and specie between New York and New Orleans, with an intermediate stop at Havana, Cuba.

[11] De Soto became one of the last steamships to engage in trade between the North and the breakaway Southern states when she departed New York for New Orleans on 23 April 1861, eleven days after the outbreak of the Civil War.

[4] The steamer put to sea on 19 November with ordnance stores for Fort Pickens, Florida, and vessels in the Gulf of Mexico, arriving off Southwest Pass, Mississippi River, after 11 December.

Given the sometimes light winds of the Gulf and inshore waters, the vessel's shallow draft and steam power gave De Soto an advantage over her mainly sail-powered prey.

Walker's first month in the region began poorly, however, when his ship collided with the French war steamer Milan, then adrift off South West Pass, Mississippi River.

[4] In spite of this initial mishap, De Soto's first capture did not take long, as she and a bluejacket-crewed lugger took schooner Major Barbour off Isles Dernières, Louisiana on 28 January 1862.

[4] Three months of hot weather and lack of maintenance facilities took a toll on De Soto's boilers and she returned to New Orleans, Louisiana, for temporary repairs in early October.

A backlog of work and lack of funds forced Rear Adm. David Farragut to send De Soto north, however, and the steamer arrived at the Philadelphia Navy Yard only on 18 November.

[1] De Soto stood down the Delaware River on 3 February 1863 and, after stops at Havana, Cuba and Santo Domingo, arrived back at Key West, Florida on the 15th.

This was demonstrated on 24 April, when De Soto sailors boarded and seized two sloops, Jane Adelie and Bright, sixteen hours out of Mobile, Alabama, and each laden with cotton.

On 27 April, De Soto continued the run of good luck, seizing the British schooner Clarita en route from Havana, Cuba to Matamoras.

[4] Returning to sea in mid-June, De Soto's luck held and she captured schooner Lady Maria north of Tampa Bay on 6 July, laden with 104 bales of cotton.

[4] De Soto continued her patrols in the Gulf of Mexico into the month of August, braving the sweltering heat to board and inspect coastal and seaborne traffic.

De Soto proceeded to Havana in late February, for dry docking and repairs to her hull, before taking up a patrol station off the east coast of Florida in mid-March.

[4] At this time, "revolutionists" in Haiti were fighting the government of President Geffrard from a base at Cap-Haïtien, and De Soto steamed to that port to safeguard Americans residing in that area.

[4][15] De Soto withdrew the next day as well, carrying the wounded British sailors to Jamaica before putting into Port-au-Prince, to debark the many foreign refugees picked up at Cape Haiten.

There, he negotiated with a British squadron under Captain Macguire in HMS Galatea in the hopes of averting a retaliatory bombardment of the town, particularly as the Americans feared such an act would provoke widespread unrest and attacks on foreigners throughout Haiti.

[4] As the revolutionary disturbances in, and friction between, Haiti and the Dominican Republic continued apace, De Soto returned to the West Indies in June, arriving at Port-au-Prince on the 19th.

De Soto proceeded south along the Florida coast on 22 October, stopping at Tampa Bay and Key West before arriving at St. Thomas, Virgin Islands, on 17 November.

The ship, in company with sidewheel steamer Susquehanna and screw sloop-of-war Monongahela, was there as part of Secretary of State William H. Seward's plan to purchase the Danish West Indies.

[4] After completing more substantial repairs over the winter, De Soto sailed to Venezuela on 3 March 1868, to secure the release of crewmen from the whaling schooner Hannah Grant, who had been captured on the peninsula of Paraguano.

[4] On 30 September 1868, De Soto was resold to her original owners, now known as Livingston, Fox & Co. After a thorough reconditioning,[1] she was returned to service as a commercial steamship, operating on her old route between New York and New Orleans with a port of call at Havana.