Organization 

The Fifteenth Wisconsin Infantry Regiment (15th Wisconsin Infantry Regiment) organized at Camp Randall, Madison, WI. They mustered into the service of the United States on February 14, 1862.  They left the state on March 2, 1862, traveling to Birds Point, MO., and reaching there on March 14th. 

Active Duty 

In Missouri, they took their place in line with the forces investing Island Number 10. They, they remained until the end of the siege of Island 10 on April 8, 1862. Soon after the surrender of the Confederate forces the Fifteenth was transferred to Tennessee. Subsequently, their service was provided in Kentucky, Tennessee, and Georgia. In summer 1862, they participated in many Union force movements. In fall, they met the confederate forces at Perryville (also known as Chaplin Hills), Kentucky, and took part in the battle on October 8, 1862.   

With the Union forces, they pursued the retreating Confederates and reached Nashville, TN around the middle of November.  Then, around December 26, as a part of the Army of the Cumberland, they took part in the movement toward Murfreesboro, TN. Following that, they participated in the battle of Stones River (also known as Murfreesboro), from December 30, 1862, to January 1, 1863.  

Afterwards, the Fifteenth served in various expeditions in middle Tennessee. With the Army of the Cumberland under Gen. Rosecrans, they took part in the Tullahoma Campaign from June 23 to July 7, 1863. Subsequently, they participated in the advance into Northern Georgia near Chattanooga. They participated in the battle of Chickamauga, GA, from September 19 to 20, and in the subsequent battle of Missionary Ridge, Chattanooga, TN. on November 25, 1863. These battles were followed by service in the campaign to relieve the forces under Gen. Burnside at Knoxville, TN.  

Returning to Chattanooga, the regiment joined Sherman’s Army on May 5, 1864. Then, they participated in the Atlanta Campaign from May 1 to September 8, 1864.  They took part in the battles of Resaca on May 14, 1864.  

They also participated in the operations at Dalton on May 26, 1864, and at Kennesaw Mountain on June 23, 1864. Later, they engaged in the siege of Atlanta on July 22, 1864, and the battle of Jonesborough on September 1, 1864. 

After the conclusion of the Atlanta Campaign, the Fifteenth returned to Chattanooga. There, most of the companies were mustered out of service of the U.S. in December because their terms had enlisted.  

 Two companies, A and E, remained at that place until the February 13, 1865, when these companies were mustered out.  A portion of the men whose term of service had not at that time expired were transferred to the Twenty-Fourth Infantry, and subsequently upon muster out of that regiment to the Thirteenth Infantry, with which regiment these men served until muster out of service of the Thirteenth. 

Therefore, Companies A, B, and E mustered out on December 1, 1864. Then, Company C mustered out on January 1, 1865. Next, the Companies F and G mustered out on January 14, 1865. The Companies I and K mustered out February 11. Lastly, Companies D and H mustered out on February 13, 1865.  

Casualties 

The Fifteenth Regiment lost 8 officers and 86 men to mortal wounds. They lost an additional officer and 241 men to disease. 

For Further Research

Search our collections for photos and artifacts from Wisconsin in the Civil War. Read about other Wisconsin Civil War regiments. For detailed regimental histories of the U.S. Civil War, consult the Frederick H. Dyer, Compendium of the War of the Rebellion: Regimental Histories.

The histories above, unless otherwise noted, are adopted from Charles E. Estabrook, ed., Records and Sketches of Military Organizations, (Madison, 1914).