Iowans, particularly those from Cedar Falls, served in both the eastern and western theaters of the war. However, the vast majority of them were to serve in the western theater. The western theater was for the most part under the command of General Ulysses S. Grant. Both the 3rd and the 31st Iowa Infantries, the units in which most of the soldiers from Cedar Falls served, were to be under the command of Grant for most of the war.

The first combat situation to be faced by soldiers from Cedar Falls occurred at a place called Hager's Woods on July 8, 1861. "The Union troops had three men wounded in the brief exchange but no one was killed." (7) The men from Cedar Falls would also see action at a place called Monroe Station the next day, but again no one was killed. The next combat seen by the soldiers from Iowa came at a place called Blue Mills. Blue Mills is significant in the history of Cedar Falls because it is the place where the first "hometown boy" was killed during the Civil War. "The Pioneer Greys had their first man killed, Private James Brownell." (8) The next major battle that the men from Cedar Falls participated in was the battle of Shiloh, in April 1862. Shiloh was one of the bloodiest battles of the war, and the 3rd Iowa paid heavily. Throughout the entire first day of the battle the men of the 3rd Iowa were involved in some of the heaviest fighting. The Union army received reinforcements on the second day and as a result "the Pioneer Greys were assigned to the reserves and were able to watch part of the battle from the bluffs." (9) Next on the agenda for the troops from Iowa was the battle for Vicksburg, which lasted from December 1862 until July 1863. By this time the 31st Iowa had been formed, which included John Rath. The struggle for Vicksburg was a long and drawn out one which lasted over six months. By the time Vicksburg fell thousands of Union soldiers had died, the majority of them from disease. Kenneth Lyftogt, author of From Blue Mills to Columbia, notes that "the winter campaign against Vicksburg was one of the most severe tests of endurance and patriotism yet experienced by the Union soldiers. The camps at Milliken's Bend and Young's Point were death traps of filth and disease." (10) Vicksburg finally fell on July 4th, 1863. This proved to be a decisive victory for the Union because it severed the Confederacy and gave the Union total control of the Mississippi River. After the fall of Vicksburg, Grant's army moved through Mississippi and headed towards Tennessee and Georgia. It was at the battle of Missionary Ridge, on November 25, 1863, in Tennessee that John Rath's brother George lost his life. At this point of the war, late 1863--1864, General Grant assumed overall command of the Union armies. This meant that the majority of the soldiers from Iowa would now be under the command of General William T. Sherman. After the Union had driven the Confederate army out of Tennessee it converged on Atlanta. After taking Atlanta, the Union troops under Sherman, the 3rd and 31st Iowa included, participated in the infamous March to the Sea, during which the Union army left a wide swath of destruction through northern Georgia. By this time the war was all but decided and the troops from Iowa spent the remainder of it chasing the remnants of the Confederate army through the Carolinas.