The 9th Connecticut Infantry Regiment 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 antebellumstate 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 9th was part of Brigadier GeneralBenjamin Butler’s "New England Brigade" organized for the capture of New Orleans. The Ninth included James T. Mullen.[2]
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.
Bruce, Susan Ural (2006). The Harp and The Eagle: Irish American Volunteers and the Union Army, 1861-1865. New York: New York University Press. ISBN0-8147-9939-6.