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.
