15th Illinois Infantry

== Regimental History and Service Record ==
Organized at Freeport, Ill., and mustered in May 24, 1861. Ordered to Alton, Ill., June 1, 1861, and duty there until July 15, 1861. Moved to St. Charles, Mo., thence to Hannibal, Jefferson Barracks and Rolla, Mo., July 15-August 7. Advance toward Columbus August 29-September 8. Join Fremont's Army at Tipton, Mo., October 1. Attached to Dept. of Missouri to February, 1862. 1st Brigade, 4th Division, District West Tennessee, to March, 1862. 2nd Brigade, 4th Division, District of West Tennessee, and Army of the Tennessee, to July, 1862. 2nd Brigade, 4th Division, District of Memphis, Tenn., to September, 1862. 2nd Brigade, 4th Division, District of Jackson. Tenn., to November, 1862. 2nd Brigade, 4th Division, Right Wing 13th Army Corps (Old), Dept. of the Tennessee, to December, 1862. 2nd Brigade, 4th Division, 17th Army Corps, Army of the Tennessee, to January, 1863. 2nd Brigade, 4th Division, 16th Army Corps, to July, 1863. 2nd Brigade, 4th Division, 13th Army Corps, to August, 1863. 2nd Brigade, 4th Division, 17th Army Corps, to November, 1864. 1st Brigade, 4th Division, 17th Army Corps, to April, 1865. 2nd Brigade, 4th Division, 17th Army Corps, to June, 1865. Dept. of Missouri to September, 1865.
SERVICE.--Fremont's advance on Springfield, Mo., October 13-November 3, 1861. Moved to Sedalia, thence to Otterville, and duty there until February, 1862. Moved to St. Louis, Mo., thence to Fort Donelson, Tenn., February 1-16. Capture of Fort Donelson February 16. Expedition to Crump's Landing and occupation of Pittsburg Landing, Tenn.. March 14-17. 
* April 6-7, 1862 - Battle of Shiloh, Tennessee
Advance on and siege of Corinth, Miss., April 29-May 30. March to Memphis, Tenn., via Grand Junction, Holly Springs and Lagrange, June 1-July 21. Duty at Memphis until September 6. March to Bolivar and forced march to Hatchie River September 6-October 4. Battle of Hatchie River, or Metamora, October 5. Grant's Central Mississippi Campaign. Operations on the Mississippi Central R. R. from Bolivar to Coffeeville October 31, 1862, to January 10, 1863. Duty at Memphis, Tenn., until May, 1863. Ordered to Vicksburg, Miss., May 13. 
* May 18-July 4, 1863 - Siege of Vicksburg, Mississippi
Advance on Jackson, Miss., July 4-10. Siege of Jackson July 10-17. Assault on Jackson July 12. Reconnaissance to Pearl River July 15. Moved to Natchez, Miss., August 15, and duty there until November 10. Expedition to Harrisonburg September 1-7. Near Harrisonburg and capture of Fort Beauregard September 4. Moved to Vicksburg, Miss., November 10, and duty there until February, 1864. 
* February 3-March 2, 1864 - Expedition from Vicksburg, Mississippi to Meridian, MississippiOriginally referenced March 5 on unit homepage
Champion's Hill, Baker's Creek, February 4. Movement to Cairo, Ill., thence to Clifton, Tenn., and march to Ackworth, Ga., via Huntsville and Decatur, Ala., and Rome, Ga., April 28-June 8. 
* June 8-July 1, 1864 - The Atlanta Campaign
** Assigned to garrison duty at Allatoona Pass, Ackworth, Big Shanty and Marietta until November. 
** Regiment consolidated with 14th Illinois Infantry on July 1, 1864, as 14th and 15th Illinois (Consolidated) Infantry Battalion. 
* Regiment reorganized from 14th and 15th Battalion at Raleigh, N. C., April 28, 1865.
== Regimental Roster ==
 
 
 Field and Staff Officers
 
 
 Regimental Band
 
 
 Company A
 
 
 Company B
 
 
 Company C
 
 
 Company D
 
 
 Company E
 
 
 Company F
 
 
 Company G
 
 
 Company H
 
 
 Company I
 
 
 Company K
 
 
 Unassigned
 
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== Regiment Statistical Information ==
* Regiment lost during service 6 Officers and 81 Enlisted men killed and mortally wounded and 5 Officers and 135 Enlisted men by disease. Total 227.
== Legacy ==
== Notes ==
== Sources == 
* (Pages 703, 720, 779, 784, 834, 846, 1050-1051)
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