Tioga – one of 12 double-ended steam gunboats laid down in the summer and fall of 1861 – was launched by the Boston Navy Yard on 18 April 1862; sponsored by Mrs. H. P. Grace; and commissioned on 30 June 1862, Lt. George W. Rodgers in command.

While in the James River Flotilla, Tioga escorted supply ships and frequently exchanged fire with Southern batteries and sharpshooters ashore.

One of her more unusual duties during this assignment was the chore of protecting the barge which carried and launched an observation balloon to reconnoiter Confederate positions and troop deployments.

During much of August, Tioga helped to cover the movement of Union troops as McClellan evacuated the peninsula between the James and the York Rivers and transferred his troops north by water to protect Washington, D.C. After the withdrawal had been largely completed, the James River Flotilla was broken up on 29 August, with a dozen of its ships being transferred to the Potomac Flotilla and the remainder reverting to the direct control of Rear Admiral Louis M. Goldsborough, who commanded the North Atlantic Blockading Squadron.

However, before Tioga could become an effective part of the Potomac Flotilla, a change of orders reassigned her to the newly established West India Squadron, formed – under the command of Commodore Charles Wilkes – to counter the threat posed by the recent commissioning of the Confederate commerce raider Florida and the expected activation of the steam warship then being built for the South in England under the designation 290 which would prey on Northern shipping as Alabama.

When they noticed a large quantity of cotton floating in the water, Tioga and Octorara hove to and picked up the jettisoned cargo, while Santiago de Cuba kept up the pursuit and overtook the English steamer Victory which she sent to Boston, Massachusetts, under a prize crew.

She took an unidentified schooner – laden with salt, liquors, coffee, arms, and other items badly needed by the South – off Grand Bahama Island on 4 January 1864.