Iowa in the American Civil War

The Civil War era brought considerable change to Iowa's politics. During the 1850s, the state's dominant Democratic Party developed serious internal problems, as well as being unsuccessful in getting the national Democratic Party to respond to their local needs. Iowans soon turned to the newly emerging Republican Party. The new party opposed slavery and promoted land ownership, banking, and railroads, and Iowa voted heavily for Abraham Lincoln and other Republican politicians in 1860 and throughout the war, though there was a strong antiwar "Copperhead" movement among recent settlers of Southern origins. The Democratic party remained particularly in places around the Mississippi River such as Dubuque that had been heavily settled by German immigrants.

As the Civil War erupted, Governor Samuel J. Kirkwood led efforts to raise and equip volunteer troops for the Federal service. The 1st Iowa Infantry was raised for three-months duty from May until August 1861. It helped secure the strategic Hannibal and St. Joseph Railroad in northern Missouri, then endured a series of forced marches across the state, finally fighting with distinction in the Battle of Wilson's Creek, a task rewarded by the official Thanks of Congress, and two Iowans would later be awarded the Medal of Honor for their efforts in the fighting.

There were no significant battles in Iowa, but the state sent large supplies of food to the armies and the eastern cities. 76,242 Iowa men (out of a total population of 674,913 in 1860) served in the military, many in combat units attached to the western armies. 13,001 died of wounds or disease (two-thirds of whom were of the latter). 8,500 Iowa men were wounded. Cemeteries throughout the South contain the remains of Iowa soldiers who fell during the war, with the largest concentration at Vicksburg National Cemetery. A number also died in Confederate prison camps, including Andersonville prison. Though the total number of Iowans who served in the military during the Civil War seems small compared to the more heavily populated eastern and southern states, no other state, north or south, had a higher percentage of its male population between the ages of 15 and 40 serve in the military during the course of the war.

Iowa contributed 48 regiments of state infantry, 1 regiment of black infantry (the 1st Iowa Volunteer Infantry Regiment (African Descent)), 9 regiments of cavalry, and 4 artillery batteries. In addition to these Federally mustered troops, the state also raised a number of home guard or militia units, including the Northern Border Brigade and Southern Border Brigade, primarily for defense of the borders, but with a commission from governor Kirkwood authorizing the border brigades to cross into Missouri (or into Minnesota and Dakota Territory) to pursue Confederate or Indian raiders as the case may be. Both the Ho Chunk (Winnebagos) and the Santee band of the Sioux nation posed the biggest threat to Iowa's northwestern border. Other local units included the Sioux City Cavalry—a militia company which, however, was subsequently mustered into US service and deployed to Dakota Territory after the Santee Sioux Uprising of 1862 and became General Alfred Sully's Headquarters Guard during the Union Army's subsequent "Punitive Expeditions" against 700 renegade Santee Sioux in 1863 and 1864. Sully selected the Sioux City Cavalry as his escort and guard over several other cavalry units because of the previous experience of its members who had worked for years before the war as trappers, traders and teamsters along the Military Road running from the US Army logistics depot at Sioux City northwest to the Dakota Territorial capital at Yankton and onward to Fort Randall which, at that time, was the largest US Army post on the upper Missouri river. As such these militia troopers were thoroughly experienced with other Sioux bands—such as the Yankton and Yankonais—and knew their sign, their language, and their customs. Likewise, the 6th Iowa Cavalry and one battalion of the 14th Iowa Infantry were deployed to Forts Randall, Pierre and Berthold, Dakota Territory as part of the same campaigns against the Santee renegades.

Sporadically, Confederate partisans and bushwhackers raided Iowa. One such incursion in the fall of 1864 was designed to disrupt the reelection of Abraham Lincoln. Near the Missouri border, many Iowans were pro-slavery, anti-Lincoln Confederate sympathizers, and they provided a safe haven for guerrillas. On October 12, 1864, a dozen raiders disguised as Union soldiers terrorized Davis County, where they looted residences and kidnapped and murdered three Iowans near Bloomfield.