21st Iowa Volunteer Infantry Regiment The 21st Regiment Iowa Volunteer Infantry was an infantry regiment that served in the Union Army during the American Civil War . Service . The 21st Iowa Infantry was organized at Dubuque , Iowa . Individual companies were separately mustered in August and the regiment was mustered in for three years of Federal service on September 9 , 1862 . On a rainy September 16th , the regiment left Dubuque ' s Camp Franklin crowded on board the Henry Clay and two barges tied alongside . Low water at Montrose forced them to go ashore , travel by rail to Keokuk , board the Hawkeye State and continue their journey to St . Louis where they arrived on September 20 , 1862 . On the 21st , they left by rail and on the 22nd arrived in Rolla , Missouri . A month later they moved south to Salem and then to Houston , Missouri , forming as part of a brigade that included the 21st Iowa , 99th Illinois , and 33rd Missouri regiments as well as detachments from the 3rd Missouri Cavalry , 3rd Iowa Cavalry , and from the 1st Missouri Artillery . This brigade was under the command of Gen . Henry Fitz Warren . On November 24 , 1862 , some members of the regiment were serving as teamsters and guards with a wagon train bring supplies from the Rolla railhead to the regiment then in Hartville . That evening , while camped along Beaver Creek , they were attacked . One man was killed and two were mortally wounded . Colonel Merrill then moved them back to the safer confines of Houston . When word was received that a rebel force was moving north from Arkansas , a relief force of 25 volunteers from each company , an officer from each company , Lt . Col . Dunlap to lead them , and Col . Sam . Merrill in command of the entire force that included a similar number from an Illinois regiment left Houston . At Hartville , on January 11 , 1863 , they engaged in a one - day battle with the Confederates led by John Marmaduke . At the end of the day , the Confederates withdrew to the south toward Arkansas and the Federals north to Lebanon and then back to Houston . Following their service in Missouri , the regiment was formed with the 22nd Iowa , 23rd Iowa , and 11th Wisconsin regiments in March , 1863 , to form the 2nd Brigade ( Big Mike Lawler ' s Brigade ) of Gen . Carr ' s Division , of the 13th Army Corp under U . S . Grant to participate in the Vicksburg campaign . The brigade saw action in Mississippi at Port Gibson on May 1 , 1863 . During the Battle of Champion ' s Hill on May 16 , 1863 , they were held in reserve by General John McClernand and saw no action . The next day they were rotated to the front and , with the 23d Iowa , routed entrenched Confederates at the Big Black River Bridge . They did not participate in the May 19th assault at Vicksburg , but did participate in the May 22nd assault and the ensuing siege . The brigade distinguished itself at the Big Black River , charging out of a meander to the enemy ' s left flank causing the Rebel defenses at the Black River bridge to collapse and forcing them to retreat . A Northern newspaper correspondent called the three - minute assault the most " ludicrous " he had seen . With the path to Vicksburg now unimpeded , the rest of the army hurried forward and quickly enveloped the city . Lawler ' s brigade distinguished itself again at Vicksburg . On the 22d it brigade charged up the slopes toward the Texans waiting at the top in the railroad redoubt . After fierce fighting , the brigade controlled the ridge at the top for a few hours before being driven off . Gen . Grant abandoned his efforts to take Vicksburg by force and settled into a prolonged siege which ended with Gen . Pemberton ' s surrender of his Confederate forces and the city on July 4 , 1863 . An impressive memorial near the redoubt honors the Iowans who fought and those who sacrificed themselves in the Vicksburg Campaign . From May 1 through the end of the siege , the regiment suffered 31 killed in action , 34 mortally wounded and 102 with wounds less severe but many serious enough to cause the men to be discharged . Following Vicksburg , the regiment was part of a force that marched on Jackson , MS . The regiment then took part in various actions in southwestern Louisiana and before leaving New Orleans for Texas on November 23 , 1863 . In Texas they were stationed on Matagorda Island and at Indianola . On February 22 , 1864 , five members of the regiment were captured near Green Lake . The regiment finally saw action in the Mobile campaign , taking part in the caputulations of Ft . Blakely and Spanish Fort , but not participating in assaults on either fort . After occupying the city , they camped at Spring Hill , before being transported back to New Orleans . Their final service was in Arkansas . The regiment was mustered out on July 15 , 1865 , at Baton Rouge and discharged at Clinton , Iowa , on July 24 , 1865 . The book by George Crooke contains numerous errors due perhaps to its having been written so long after the war by which time many members of the regiment had died and others had left the area and since its author , although a member of the regiment and capable officer , was absent from January 1863 to June 1864 a period which included the entire Vicksburg Campaign and all of the regiment ' s service in Texas .