CSS GENERAL M. JEFF THOMPSON (1862)
Built: Unknown; possibly New Orleans or Algiers, Louisiana
Commissioned: April, 1862
Service: River Defense Fleet, 1862
Home Port: Memphis, Tennessee
Armament: 1xSmoothebore (size uncertain, likely 30, 32, or 42lb); see notes below for further information.
Engines: Dual Paddlewheel
Speed: Unknown; estimated at 9-10 Knots.
Fate: Ran aground and blew up at the Battle of Memphis.
We know precious little about CSS General M. Jeff Thompson, occasionally referred to as "M. Jeff Thompson" or simply "Jeff Thompson" in existing records and accounts. Interestingly enough, General M. Jeff Thompson himself actually served in the River Defense Fleet during her service! According to an article on Wikipedia, conversion began around January 25th from a civilian steamer of unknown name and designation. At the time of writing, I have been unable to confirm this detail, but it seems to fall within a reasonable timeframe. Her dimensions are generally unknown, but her speed was probably around 9-10 knots, since the commander of the River Defense Fleet, Captain J.E. Montgomery, often claimed that all of the vessels in his fleet could make at least that speed. Angus Konstam proposes that she was armed with a single, bow mounted pivot gun, a smoothebore of unspecified size. Given the tendencies in both fleets at the time, this was likely a 30, 32lb or 42lb weapon.
At the Battle of Plum Point, M. Jeff Thompson was unable to find a suitable target for ramming, but did engage elements of the Western Gunboat Flotilla with her gun(s). She is said to have maintained a cool, professional rate of fire despite the heavy volume of fire directed back at her by the Union ironclads.
Like most of the rest of the River Defense Fleet, she met her end at the Battle of Memphis. At some point during the engagement, she received a critical hit to her main boiler, ran aground in the ensuing chaos, and promptly blew up. The fatal blow may have been dealt by the Western Gunboat Flotilla's flagship, USS Benton.
As of the time of this update, a source has come to light claiming that all ships of the River Defense Fleet present at the Battle of Plum Point were equipped with "at least four eight inch guns." If this is true, the guns would likely have been 8" Smoothebores, very common weapons in use on the Mississippi.