9th Connecticut Infantry Regiment The 9th Regiment Connecticut Volunteers was a volunteer infantry regiment in the Union Army during the American Civil War . It was established in September 1861 as an Irish regiment , composed mainly of soldiers born in Ireland or first generation Irish Americans . The regiment saw action in number major battles , particularly in the Western Theater . Organization and early service . The 9th Infantry was formed in September 1861 , primarily using recruits whose terms of enlistments in Connecticut ' s early three - months regiments had expired . Its first field officers were relatively experienced soldiers . Colonel Thomas W . Cahill of New Haven had a number of years experience with the antebellum state militia as captain of the Emmet Guards , while Lieutenant Colonel Richard Fitzgibbons and Major Frederick Frye had both served as captains of three - month companies at the First Battle of Bull Run in July . Although recruitment at Camp English in New Haven proceeded slowly due to the lack of proper clothing and equipment , the regiment had 845 men when it left New Haven in November by rail for Camp Chase in Lowell , Massachusetts . There , the 14th was part of Brigadier General Benjamin Butler ’ s " New England Brigade " organized for the capture of New Orleans . Duty in Mississippi . Before the end of the month , they left Boston Harbor as part of more than 3 , 000 troops on board the steamer " Constitution " . They arrived at Ship Island , Mississippi , on December 3 , where they supplied with arms and some improved clothing . After early action at Biloxi and Pass Christian , the regiment was directed by General Butler to make a public parade through the city to discourage any outbreaks against Federal authorities . On June 25 , 1862 , the unit was put to work upriver on a canal opposite Vicksburg along with regiments from Massachusetts , Vermont , Michigan and Wisconsin , all under the direction of General Thomas Williams . The canal was intended to connect a loop in the Mississippi River and allow Union ships to bypass the cannons on the bluffs at Vicksburg and have free access from the north to the Gulf of Mexico . However , lack of drinking water , supplies and medicine , as well as the summer heat and exposure quickly took its toll as heatstroke , malaria , and dysentery spread rapidly . With many dying or incapacitated , slaves from nearby plantations were added to the workforce , but , as the water level fell in the river , the canal attempt was abandoned on July 24 and the troops were moved downriver to Baton Rouge , Louisiana . A boat , the " Algerine " , with 300 sick on board , was left behind with Surgeon Gallagher of the 9th in charge . In a four - month span from July to October 1862 , 150 men from the Ninth Regiment alone died of disease . Subsequent service in Louisiana and Virginia . At Baton Rouge , Louisiana , Williams was killed under a Confederate charge on August 5 . Colonel Cahill took command of all the Union troops and repulsed the attack . The regiment was highly praised after the battle and subsequently assigned to the defenses of New Orleans through the end of 1863 . In the spring of 1864 , the regiment arrived home in New Haven on veteran furlough amidst great celebration and parades . The re - enlisted veterans landed at Bermuda Hundred , Virginia , outside Richmond in July and participated in a engagement at Deep Bottom . After a brief trip to the Washington D . C . area , they saw action in the Shenandoah Valley area with battles at Opequon , Cedar Creek , and Fishers Hill . The final veterans were mustered out in August 1865 . A total of 250 men from the regiment died during the war . John C . Curtis , the regiment ' s 17 - year old sergeant major , received the Medal of Honor for his actions at Baton Rouge in August 1862 .