Dennis: I am not actively researching the 11th Missouri Infantry Regiment (Union), but here are some references that may assist you in doing so:

Annual Report of the Missouri Adjutant General – 1864, 82-86. Mo State Archives, Jefferson City, Mo.

Annual Report of the Missouri Adjutant General – 1865, 142-151. Mo State Archives.

Compiled Service Records, Reels 469-486. National Archives. Washington D. C.

William W. Cleland Letter, 1861. Worcester (Mass) Aegis and Transcript, November 2, 1861. Copy on file at Mo State Archives.

William W. Cleland Letter, 1861. Chelsea (Mass) Telegraph and Pioneer, November 9, 1861. Copy on file at Mo State Archives.

Descriptive Roll, 1861. Reel 963. Mo State Archives.

Descriptive Roll, 1863. MS292, Special Collections, Fondren Library, Rice University, Houston, TX.

Dyer, Compendium, Vol. 2, 1327-1328.

Thomas S. Hawley Papers, 1861-1865. Mo Historical Society, St. Louis, Mo.

Henney, George W., “The 11th Missouri at Corinth.” National Tribune, June 28, 1894.

Hewett, Supplement to the Official Records, Serial 48, 746-824.

McCall, D., Three Years in the Service: A Record of the Doings of the Eleventh Regiment Missouri Volunteers. Springfield: Baker and Phillips Co., 1864.

David McKnight Diary Extract, 1862-1864. Mo Historical Society, St. Louis, Mo.

Record of Movements and Activities. RG 94, Reel 98. National Archives.

Regimental Books and Papers. RG 94. National Archives.

Register of Officers. Reel S938. Mo State Archives.

Register of Troops. Reels S981-982. Mo State Archives.

Service Records. Reels S852-853. Mo State Archives.

Stewart, William S. "William S. Stewart Letters, January 13,1861 to December 4,1862.” Part 1. Edited by Harvey L. Carter and Norma L. Peterson. Missouri Historical Review 61 (January 1967): 187-228; Part 2,.61 (April 1967): 303-320; Part 3, 61 (January 1967): 463-488.

William S. Stewart Papers, 1861-1864. Western Historical Manuscript Collection, U. of Mo-Columbia (Same as above)

Temple, Wayne C., “A Chaplain in the 11th Missouri Infantry.” Lincoln Herald (Summer 1962): 81-88.

Suhr, Robert Collins, “Attack written Deep and Crimson.” America’s Civil War 24 (March 1985): 46-52.

I hope that this helps you some.