The first USS Milwaukee was a double turreted river monitor that was launched by James B. Eads at Carondelet, Mo. on 4 February 1864 and commissioned at Mound City, Illinois. on 27 August 1864 with Acting Volunteer Lt. James W. Magune as the commanding officer.
The Milwaukee departed Mound City on 15 October 1864 to join the West Gulf Blockading Squadron in New Orleans, Louisiana. There she prepared for action against the Confederate troops in Mobile, Ala. On 22 November Lt. Comdr. James H. Gillis took command of the ship and set a course for Mobile. Rear Admiral Farragut had previously won a decisive victory in Mobile Bay 5 August, however the city itself was still in Confederate hands. To defend it, the South heavily mined the shallow water which led to the city, filled it with formidable obstructions and erected batteries to shell any ships which managed to penetrate the fixed defenses. On New Year’s Day 1865 Milwaukee arrived at Mobile Bay ready for action. In the following months, with other light‑draft Union ships, she swept mines, bombarded Confederate works, removed obstructions and transported Army troops.
General Canby, the Union Army commander, decided to attack the city from the east by the rivers which connected it with the bay, rather than the west where it was protected by strong sea ports. The key to the city was Spanish Fort which lay on the east bank of the Blakely River. Canby began to deploy his forces 17 March, and 10 days later reached Spanish Fort and put it under siege. That day, 27 February, Milwaukee and five other Union ships crossed Dog River Bar to cut communications between the fort and Mobile. On the afternoon of the 28th the Milwaukee and the Winnebago steamed up Blakely River to attack a Confederate transport supplying Spanish Fort. After forcing the Southern ship back, the Milwaukee struck a torpedo mine on the port side and quickly sank (though her entire crew was saved).
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