The other unit that the men of Cedar Falls joined in great numbers was the 31st Iowa Volunteers. This happened to be the unit that John Rath and his brother George joined. The 31st Iowa was formed at a later date than the 3rd Iowa. This was because many people, both in the North and the South, had expected the war to end quickly. This, however, was not to be the case. The 31st Iowa was formed as a result of another call to arms by President Abraham Lincoln. "On 2 July 1862, President Lincoln issued a call for 300,000 soldiers to be enlisted for a period of three years; Iowa's quota was over 10,000." (4) The Cedar Falls Reserves were formed and became a part of the 31st Iowa by August of 1862. The diary of John Rath is important when considering the history of the Civil War in Cedar Falls because it is one of the few complete accounts by a Cedar Falls native that still exists today. Rath's career as a soldier began on August 2, 1862, when he answered Lincoln's aforementioned call to arms. The diary is interesting because it allows the reader to examine the life of a soldier during the Civil War firsthand. Rath’s style of writing is often terse, but is sufficiently detailed to effectively convey the horrors of war. One of the first things that Rath was asked to do as a soldier was to bring the dead bodies of his comrades back behind the Union lines. "December 30. All quiet. Went out to bring in the dead and wounded which was agreed upon. About one hundred were brought in, stripped of all clothing, a hard looking sight." (5) Later in the war Rath comments on the perils of a march in the hot summer weather.

Weather awful hot and many die on the road. I went to our old camp on the line which some of our sick were left on. In other words, half the command here. We stayed until the first of August, not getting any better and weather very hot . . . We remained here in Camp Sherman about two months where we lost a good many men by sickness. I was sick for six weeks until the weather got colder.

This passage is indicative of the way the war went for many soldiers. A large majority of the casualties suffered by both sides during the war were the result of disease and sickness, not combat. Rath faithfully recorded the events of the war as he saw them until the end of his service, which did not occur until several months after the war ended.