The Thirteenth Infantry Regiment was organized at Janesville, WI, and mustered into the service of the United States on October 17, 1861. It left the state January 18, 1862, under orders to proceed to Fort Leavenworth, Kansas, which it reached early in February. The regiment was at once detailed for active service, and on February 7 it marched to Fort Riley, Kansas, and was on duty in that vicinity until April 28. It returned to St. Louis and was assigned to guard duty east of the Mississippi River on the lines of railway between Columbus, KY, and Corinth, MS.
On August 25, the Thirteenth was transferred to Fort Henry on the Tennessee River and participated in various expeditions in middle Kentucky and Tennessee during the greater part of the year in1862. In February and March, 1863, the Thirteenth was stationed at Fort Donelson on the Cumberland River; in September at Stevenson, AL, and later in the year and until February 1864 at Nashville, TN, when, more than three-fourths of the men having re-enlisted the regiment proceeded to Wisconsin on veteran furlough. After furlough the regiment returned to the Nashville area, engaged in garrison duty and guarding trains from Louisville to Chattanooga. In April they again moved to Stevenson. From here they protected Sherman’s communications, with several severe skirmishes with rebel outposts and guerrillas. In November when Hood crossed the Tennessee, the Thirteenth was involved in efforts to block Hood’s retreat.
The general work of the Thirteenth during its long term of service was the protection of lines of communication in middle Tennessee and Kentucky and northern Alabama. This is a service which must be diligently and faithfully performed if the army at the front is to do the work assigned to it. In June 1865 the Thirteenth was sent to New Orleans and in July of that year into Texas near the Rio Grande, where the regiment remained on duty at various posts until November 24, 1865. Orders were received to proceed to Madison, WI, which was reached December 23. The Thirteenth disbanded December 26, 1865.