CSS Atlanta was born in the Clyde Bank Iron Shipyard of Scotland as the "Fingal" in 1861 and launched that May. Like other warships going on to serve the Confederate Navy during the American Civil War (1861-1865), Fingal, originally laid down as a merchant steamer, was purchased by Confederate agent James Bulloch based in England and eventually converted for the role of ironclad. As the Fingal, she made the journey across the Atlantic in 1861 and reached Bermuda on October 15th - laden with medical supplies, firearms, cannon and related ammunition. She passed through the Union blockade of Savannah on November 22nd to deliver the much-needed cargo to fighting forces.
As the Union noose around Savannah tightened to the point that a return-trip out of Savannah for Fingal was out of the question, authorities decided to convert the vessel for a more useful purpose. She was reworked into an ironclad by having her upper section completely removed. A torpedo spar was added to her bow and 2 x 7" Brooke and 2 x 6.4" Brooke rifled guns were installed as armament. 145 men (21 officers, 124 enlisted personnel) made up her complement while her propulsion scheme centered on a boiler / steam engine arrangement driving power to a single shaft. Maximum speed was reduced from 13 knots to 10 knots as armor plating and other changes completely modified her performance specs. Her length was increased from 189 feet to 204 feet and displacement ballooned from 700 tons to just over 1,000 tons. Her beam measured 41 feet and her draught was 15.8 feet. Armor protection reached 4" at the casemate, 2" at the hull and 4" at the pilothouse. Her side profile was dominated by an angled superstructure over midships and a single smoke funnel.
The work was completed by Asa & Nelson Tift of Savannah and primarily financed by the women of Savannah - like several other ships of the Confederate cause.
Of course the conversion to an ironclad had its issues - the new vessel was heavy and this made her slow and cumbersome to maneuver, as proven during her trials along the Savannah River. The fighting conditions for the crew internally were also deemed quite poor as there stood little in the way of air circulation - a huge detriment considering the stifling Georgian summer heat and humidity. Leaking also proved problematic and only resolved to a limited extent by engineers moving forward.
The warship was commissioned at CSS Atlanta on November 22nd, 1862 and she steamed out of the Wilmington River to squared off against the Union ironclads USS Nahant and USS Weehawken on June 17th, 1863. However, she managed only seven total shots in the engagement and struck a sandbar in the heat of the action - running aground. The tide worked against the vessel and she had missed all of her shots on the Federal warships as they closed. Unable to free the ship, the captain of CSS Atlanta ordered a surrender, bringing her tenure under the flag of the Confederate Navy to a quick close.
Upon her capture, the Union Navy freed the ironclad and she was taken to the Philadelphia Navy Yard for repairs. Renamed USS Atlanta, she now fought under the Union Navy flag when recommissioned on February 2nd, 1864. Her armament was also revised to 2 x 8" Parrott rifled guns (bow and stern placements) and 6.4" Parrott rifled guns (amidships).
From there she ended her days fighting her original owners, serving through blockade actions and in support of Fort Powhattan (Virginia, 1864). Most of her remaining tenure centered on the James River which gave her excellent access through the center of Virginia. With the war over, she was decommissioned on June 21st, 1865 and set to reserve status until sold off in 1869. Prepared for delivery to the government of Haiti (to serve as the "Triumfo"), she sank somewhere en route during late December with no survivors.