7th Missouri Volunteer Infantry The 7th Missouri Volunteer Infantry , commonly known as the " Irish Seventh " , was an infantry regiment that served in the Union Army during the American Civil War . In 1864 a battalion of veteran volunteers of the " Irish Seventh was consolidated with a sister Irish regiment , the 30th Missouri Volunteer Infantry ( the " Shamrock Regiment " ) and operated as a " demi - brigade " known popularly as the " Missouri Irish Brigade " Service . The 7th Missouri Volunteer Infantry was organized at St . Louis , Missouri in June 1861 and mustered in for three years service . It was often referred to as the " Irish Seventh " given the large number of Irish immigrants who were enlisted in its ranks . The regiment was a special project supported by the Federal commanders in Missouri , Brigadier General William S . Harney and Brigadier General Nathaniel Lyon . Most of the volunteers in Missouri ' s early regiments were German immigrants , and Lyon supported the creation of a regiment recruited from St . Louis ' Irish - American population to demonstrate that the Union cause in Missouri had support beyond the German - American community . Many St . Louis Irish ( the second largest immigrant community in the city ) were ambivalent about the new Republican Party and Federal military action against seceding states . In addition , Irish Americans were strong participants in the pre - war Missouri Volunteer Militia , and many resented the May 10 , 1861 Federal arrest of the Militia for suspected secession activity . The 7th Missouri was intended to attract ethnic - Irish support by focusing on the Irish community ' s " ownership " of the regiment , and make a public political statement by demonstrating that there were Irish Unionists in Missouri . Like other ethnically Irish regiments during the Civil War , the " Irish Seventh " carried a distinctive green regimental color . An article in the July 12 , 1862 " Boston Pilot " described the flag , stating that on one side the flag featured the : " Irish harp , guarded by a savage - looking wolf dog , surrounded by a wreath of shamrocks , surmounted by an American eagle , and supported on either side by flags and other implements of war . A golden halo shoots out and over the whole . On the other side is a ' sunburst ' in all its glory , with the Irish war cry as a motto - ' Faj an Bealac ! [ sic ] " The regiment was attached to Boonville , Missouri , to September 1861 . Fremont ' s Army of the West to February 1862 . Lexington , Missouri , Department of the Missouri , to July 1862 . Unattached , Pittsburg Landing , Tennessee , Army of the Tennessee , to September 1862 . 4th Brigade , 1st Division , District of Jackson Jackson , Tennessee , , to November 1862 . 4th Brigade , 3rd Division , Left Wing , XIII Corps , Department of the Tennessee , to December 1862 . 3rd Brigade , 3rd Division , XVII Corps , to April 1864 . Maltby ' s Brigade , District of Vicksburg , Mississippi , to June 1864 . 1st Brigade , District of Memphis , Tennessee , XVI Corps , to August 1864 . 1st Brigade , 2nd Division , XIX Corps , Department of the Gulf , to December 1864 . The 7th Missouri Volunteer Infantry ceased to exist on December 17 , 1864 when it was consolidated with the 11th Missouri Infantry . Detailed service . Moved to Booneville , Mo . , July 1 – 4 , 1861 , then to Rolla August 30 and to Syracuse , Mo . , October 5 – 10 . Fremont ' s Campaign against Springfield , Missouri October 21 - November 2 . Moved to Sedalia , Missouri November 10 – 14 , then to Otterville , Missouri December and duty there until February 1862 . Expedition to Blue Springs January 20 - February 3 , 1862 ( Companies B , F , and H detached from regiment November 21 , 1861 , and ordered to Kansas City . Rejoined regiment at Lexington , Mo . , February 1862 . ) Moved to Lexington , Mo . , February 3 – 10 , 1862 , and duty there until May 9 . Reconnaissance from Greenville , Missouri February 23 – 24 ( Company H ) . Skirmish at Mingo Creek , near St . Francisville , February 24 ( Company H ) . Moved to Pittsburg Landing , Tenn . , May 9 – 14 , and guard and fatigue duty there until August 15 . Moved to Jackson , Tenn . , August 15 – 29 , and duty there until October . Medon Station , Mississippi Central Railroad , August 31 . Chewalla and Big Hill October 5 . Medon Station October 10 . Moved to Corinth with McPherson and to Jackson October 14 . To Lagrange November 2 . Grant ' s Central Mississippi Campaign November 2 , 1862 to January 10 , 1863 . At Memphis , Tenn . , January 17 - February 21 . Moved to Lake Providence , Louisiana , February 21 , and duty there until April . Moved to Milliken ' s Bend , Louisiana . , April 12 . Passage of Vicksburg batteries April 22 ( detachment ) . Movement on Bruinsburg and turning Grand Gulf April 25 – 39 . Battle of Port Gibson May 1 . Bayou Pierrie May 2 . Battles of Raymond May 12 . Champion Hill May 16 . Big Black River Bridge May 17 . Siege of Vicksburg , Miss . , May 18 - July 4 . Assaults on Vicksburg May 19 and 22 . Surrender of Vicksburg July 4 . Provost duty there until June 1864 . Stevenson ' s Expedition from Vicksburg to Monroe , Louisiana , August 20 - September 2 , 1863 . Expedition toward Canton October 14 – 22 . Bogue Chitto Creek October 17 . Expedition from Vicksburg to Sunnyside Landing , Ark . , January 10 – 16 , 1864 . Meridian Campaign February 3 - March 2 . Clinto Clinton n February 5 . Veterans on furlough March to May . Non - veterans mustered out June 14 , 1864 . Veterans at Memphis , Tenn . , and Vicksburg , Miss . , until July 29 . Moved to Morganza , La . , July 29 and duty there until September 3 . Moved to mouth of White River , Ark . , September 3 – 8 and duty there until October 18 . Movement to Memphis and return October 18 – 30 . Moved to Duvall ' s Bluff , Ark . , November 9 , then to Memphis , Tenn . , November 28 . Casualties . The regiment lost a total of 186 men during service ; 4 officers and 52 enlisted men killed or mortally wounded , 2 officers and 128 enlisted men died of disease .