The 3rd Iowa Infantry did operate in that same general area in 1861. They left Keokuk June 29th for Hannibal, and the next day traveled west by rail to Chillicothe, Grand River and Utica with arms but no ammunition, haversacks, canteens, knapsacks, cartridge boxes or field officers. The Colonel and commissions for the Lt. Col. and Major did, however, arrive a few days later and accoutrements arrived on August 4 at Chillicothe. The regiment operated along the railroads and north of the Missouri River until late September. Their big fight during this time was on Sept. 17 at Blue Mills Landing on the Missouri River near Liberty.
In late September the regiment was ordered to the defense of Ft. Leavenworth and Kansas City, remaining in that area about three weeks. It then traveled by steamboat and rail to Quincy, Ill., where it remained until ordered to St. Louis on Nov. 9. On the day after Christmas, it headed out on the North Missouri Railroad which it guarded in detachments throughout the winter, headquartered at Mexico. On March 3, 1862 it was relieved by a detachment from the second battalion of the 3rd Iowa Cavalry and headed for St. Louis. There it boarded a streamer for Pittsburg Landing, TN, debarking on March 17 and going into camp with the rest of Hurlbutt's Division about a third of the way from the landing toward Shiloh Church.
The second battalion of the 3rd Iowa Cavalry was the first portion of that regiment to take the field, deploying from St. Louis on December 12, 1861 and chased and fought guerillas, broke up recruiting efforts and captured caches of military supplies across north central Missouri from that date until early August 1862. It initially deployed to Jefferson City, then Boonville, Glasgow and the adjacent country and from Dec. 25th until spring was stationed at Fulton in Callaway County. In the spring detachments were stationed in Callaway, Audrain and Monroe Counties. In July and early August, the battalion was part of the Union force that fought a series of actions against Porter's rebel command at Florida, Bott's Farm, Brown's Springs and Moore's Mill, culminating in the decisive defeat and dispersal of Porter's two-thousand-man force in the battle of Kirksville on August 6.
The battalion was then transferred to Lebanon where it performed similar work in southwest Missouri until the summer of 1863 when it joined Davidson's cavalry division for the campaign against Little Rock and was the first Union unit to that city. The battalion was finally united with the rest of the regiment in October 1863 at Benton, Arkansas.
Meanwhile, the 1st & 2nd battalions had deployed from St. Louis to Rolla in early February 1862 as part of Gen. Samuel R. Curts's Army of the Southwest and for the most part had a more traditional service experience, including fighting at the battle of Pea Ridge in March, the march across Arkansas to Helena that summer, the aborted first expedition against Arkansas Post in September and the first raid on the Mississippi Central at Grenada in late November and early December. (Two companies spent two months on detached service scouting and guarding supply trains form Rolla to Springfield and two more companies were detached for several months helping to control the area around Salem, Mo.) The two battalions were based out of Helena, Ark. for 11 months until ordered to join Gen. Grant's forces in the Vicksburg campaign June 4, 1863. Col. Bussey was immediately appointed Chief of Cavalry. The battalions helped screened Sherman's advance on and siege of Jackson after Vicksburg surrendered, destroyed railroads and in early August participated in the second Grenada raid. At the end of the month they were ordered to join Gen. Steele's campaign against Little Rock, but that city fell before their arrival. They then immediately marched to Benton where they were reunited with the 2nd battalion.
On Jan. 1, 1864 more than 600 of the men re-enlisted as veteran volunteers. The regiment came back from its veteran furlough stronger in numbers than when it left the state in 1861 and was able to maintain near full strength for the rest of the war. After re-equipping, this hard-fighting regiment served in 1864 in Mississippi against Forrest, in Missouri against Price, then again in Mississippi against Forrest, and in 1865 in Wilson's Alabama-Georgia campaign against Forrest and others. Throughout that period it was brigaded with the 4th Iowa Cavalry and the 10th Missouri Cavalry and occasionally with other units as well.