Miami was launched by Philadelphia Navy Yard on November 16, 1861, and commissioned there on January 29, 1862, Lieutenant Abram Davis Harrell in command.

The wooden-hulled gunboat was ordered February 5, 1862, to proceed to Ship Island, Mississippi for duty in the Mortar Flotilla organized to neutralize Confederate riverside forts during Admiral David Farragut's impending attack on New Orleans, Louisiana.

Miami reached Ship Island on March 19 and headed for Pass a l'Outre where she entered the Mississippi River to join Commander David Dixon Porter's flotilla.

The shelling continued intermittently until it reached crescendo before dawn on April 24 as Admiral Farragut led his deep draft, salt water fleet up the Mississippi in a daring dash past the forts.

On June 28 her guns engaged the Confederate cannon while Farragut's ships ran by the Vicksburg batteries to join the armed riverboats of Admiral Davis' Western Flotilla.

The southern attack required naval support in order to achieve success, and Flusser added meaningfully: "The ram will be down tonight or tomorrow."

It was reported that she "tore a hole clear through to the boiler" and Albemarle's captain stated that his ship plunged 10 feet into the side of the wooden gunboat.

Brigadier General Henry Walton Wessels, commanding Union troops at Plymouth, noted: "In the death of this accomplished sailor the Navy has lost one of its brightest ornaments...." Albemarle now controlled the water approaches to Plymouth and rendered invaluable support to Confederate States Army moves ashore, giving the South a taste of the priceless advantage Union armies enjoyed in all theaters throughout the war.

Albemarle's threat to Union naval supremacy in North Carolina waters was ended October 27 when Lieutenant William B. Cushing exploded a spar torpedo under the ironclad's overhanging armor, tearing a hole in her wooden hull.

Next day, Miami, accompanied by Osceola, drove off batteries which were firing on another group of transports near Harrison's Landing, Virginia on the James River.

For the remainder of the war, Miami operated in the James River now commanded by Lt. George W Graves, playing an important role in the naval effort, assisting Grant's unrelenting pressures on the Confederate capitol which finally forced Lee to surrender at Appomattox Courthouse, Virginia on April 9, 1865.