CSS Ivy CSS Ivy was a sidewheel steamer and privateer purchased by Commodore Lawrence Rousseau for service with the Confederate Navy , and chosen by Commodore George Hollins for his Mosquito Fleet . The Mosquito Fleet was a group of riverboats converted to gunboats , and used to defend the Mississippi river in the area of New Orleans during the American Civil War . As a privately owned commercial vessel , the Ivy had been known as the " Roger Williams " and the " El - Paraguay " . The " CSS Ivy " began her Civil War career as a New Orleans based privateer " V . H . Ivy " , sent out to capture Union commercial vessels after Jefferson Davis authorized the distribution of letters of marque and reprisal to private citizens after hostilities began in April 1861 . The " Ivy " did well at this , capturing four northern registered vessels , one of which was the ice breaker " Enoch Train " , which was purchased by private investors and rebuilt as the privateer ironclad ram " Manassas " . This vessel in turn was commandeered by Commodore Hollins as the CSS Manassas . The Union Blockade arrived at the mouth of the Mississippi on May 27 , 1861 , when the USS Brooklyn took up position . This event energized defense efforts in New Orleans and led to the replacement of Rousseau with Commodore Hollins in July 1861 to command the river defense . By August Hollins had established his mosquito fleet for defense of the river in the area of New Orleans . The fleet consisted of the CSS McRae , the flagship CSS Tuscarora , CSS Livingston , CSS Calhoun , CSS Jackson , and the " Ivy " . The " Ivy " , due to her large , sophisticated walking beam engine and multiple boiler propulsion system , was the fastest ship of the fleet . Because of this , Hollins made her the reconnaissance vessel of the fleet , and increased her firepower . As a privateer the " Ivy " was armed with two brass 24 - pounder smoothbore howitzers . Hollins increased her armament to an eight inch smoothbore mounted aft , and a 32 - pounder rifled gun mounted on a forward pivot position on the bow . The conventional description of " rifled 32 - pounder " is misleading , however . This gun was a former 32 - pounder smoothbore that had been " modernized " by rifling the barrel , and machining and shrinking a single layer of red hot bands of wrought iron onto the breech of the barrel to allow it to operate at much greater breech pressures . This rifling and banding allowed the gun to fire a 100 - pound ( 6 . 4 inch diameter ) conical shot or shell at much greater ranges than would be possible with 32 - pound round shot fired out of a smoothbore barrel . This modification was similar to the James rifle process used to produce siege guns , and the resulting gun tube resembled a Parrott rifle . This gun could be much more accurately described as a 6 . 4 - inch ( 162 mm ) banded rifle , and was the most powerful , long range weapon in the mosquito fleet . The " Ivy " began patrolling the Mississippi south of Forts Jackson and St . Phillip beginning in September 1861 , captained by Lieutenant Fry of the CSN . On September 19 , she encountered the USS Water Witch . The Water Witch was scouting the Head of Passes for the blockade fleet , which was planning to occupy the Head of Passes and set up a shore battery to control this strategic point . On October 5 Ivy reported the Head of Passes occupied by three vessels of the Union fleet , and shelled them with her bow pivot gun . Returning to the forts , Fry warned Hollins the Union fleet was establishing a base at the Head of Passes . Hollins decided the advance of the Blockade Fleet was a significant threat to New Orleans and moved to attack with the entire mosquito fleet . This attack resulted in the Battle of the Head of Passes a Confederate victory that routed the Blockade Fleet and sent it back to the mouth of the Southwest Passage . This victory reinforced the idea in the Confederate War Department that Flag Officer Foote ' s Union Mississippi River Squadron at the north end of the Mississippi was the greatest threat to the Confederacy . The Battle of Fort Henry , the Battle of Fort Donelson , and the Battle of Shiloh lent a lot of credibility to this idea . As a result the mosquito fleet and the " Ivy " were ordered to the upper Mississippi and took part in the Battle of Island Number 10 . Island Number 10 was a defeat for the Confederate forces involved . The mosquito fleet could not match the USS and after these ships successfully ran the Confederate batteries , and were forced to retreat . Commander McBlair CSN at Memphis , being informed that New Orleans had fallen after the Battle of Forts Jackson and St . Philip , ordered remaining Confederate vessels on the Mississippi to concentrate at Yazoo City , Mississippi , on the Yazoo River . He regarded this harbor as the only safe place remaining on the Mississippi River network for the Confederate Navy to maintain a base . This remaining refuge did not prove safe for long . In May 1863 , Rear Admiral David Dixon Porter ordered a fleet under the command of Lieutenant - commander Walker to destroy Confederate commerce on the Yazoo River . This force consisted of the USS , , , and . With the " Forest Rose " acting as a mine sweeper , this force advanced steadily up the Yazoo river , from May 24 – 31 . Fearing the capture of their vessels on the Yazoo , Confederate forces destroyed the " CSS Ivy " , Star of the West , and the transports " Arcadia " and " Magenta " .