USS Pittsburgh ( 1861 ) USS " Pittsburgh " ( 1861 ) ( often " Pittsburg " ) was a City class ironclad gunboat constructed for the Union Army by James B . Eads during the American Civil War , and transferred to the Union Navy in October 1862 . She was commissioned in January 1862 , Commander Egbert Thompson in command . Operational history . Joining Flag Officer Andrew Hull Foote ' s Western Gunboat Flotilla in river patrol duty , " Pittsburgh " attacked Fort Donelson February 14 , 1862 , and was damaged by counter - fire . The support from the gunboats contributed greatly to the capture of the strategic fort two days later . Repaired , she attacked Island No . 10 on April 3 , then ran its batteries by dark April 7 , being lashed by a heavy thunderstorm as well as the island ' s 73 guns . This daring feat made it possible for her and " Carondelet " to demolish batteries below New Madrid , Missouri that same day , clearing the way for the Army to cross the Mississippi River . " Pittsburgh " gave continued service in the lengthy series of operations which wrested control of the lower Mississippi from the Confederacy . Her flotilla , previously under Army control , came under naval command October 1 , 1862 . Lieutenant Commander William R . Hoel USN took command of the Pittsburgh at this time . Highlights of her service were the operations against Plum Point Bend , Fort Pillow and Memphis in April , May and June 1862 ; the Steele ' s Bayou Expedition of March 1863 ; and the passing of the Vicksburg batteries April 16 , 1863 . She led the attack on the batteries at Grand Gulf on April 29 and was heavily damaged during the five - and - a - half hour engagement . One of " Pittsburgh ' s " sailors , Boatswain ' s Mate John Woon , was awarded the Medal of Honor for his part in the battle . The action at Grand Gulf secured Union control of an important stretch of the river , making it possible for Grant to cross the river and attack Vicksburg from the rear . The strong Confederate river fortress surrendered July 4 , allowing President Abraham Lincoln at last to report , " The Father of Waters flows unvexed to the sea . " Patrol and bombardment missions on the Mississippi were interrupted the following year when " Pittsburgh " joined in the Red River Expedition from March to May 1864 . On March 1 , 1865 Hoel was detached from " Pittsburgh " , to take command of USS " Vindicator " ; Acting Master Morgan commanded the " Pittsburgh " until her decommissioning at Mound City , Illinois at close of the war . " Pittsburgh " was sold there November 29 , 1865 . Armament . Like many of the Mississippi theatre ironclads , " Pittsburgh " had its armament changed multiple times over life of the vessel . To expedite the entrance of " Pittsburgh " into service , she and the other " City " - class ships were fitted with whatever weapons were available ; then had their weapons upgraded as new pieces became available . Though the Dahlgren smoothbore cannons were fairly modern most of the other original armaments were antiquated ; such as the 32 - pounders , or modified ; such as the 42 - pounder " rifles " which were in fact , old smoothbores that had been gouged out to give them rifling . These 42 - pounder weapons were of particular concern to military commanders because they were structurally weaker and more prone to exploding than purpose - built rifled cannons . Additionally , the close confines of riverine combat greatly increased the threat of boarding parties . The 12 - pounder howitzer was equipped to address that concern and was not used in regular combat .