Duane E. Grout, was my great uncle, part of the 29th Wisconsin (see information below)

From a veterans grave register. Duane Grout of Fox Lake fought in the Civil War. Company. E, 29th Inf. Rgt. Enlisted Aug 21, 1862. Prisoner at Sabine Cross Roads, LA. 2nd Lt. Company. F. 53 Wis. Inf.- Mar 1, 1865. M.O. May 11, 1865.
Enlisted as a Private on 21 August 1862
Enlisted in Company E, 29th Infantry Regiment Wisconsin on 21 August 1862.
POW on 08 April 1864 at Sabine Cross Roads, LA
Promoted to Full Lieutenant 2nd Class on 01 March 1865 (As of Co. F, 53rd Inf, not mustered)
Mustered out Company E, 29th Infantry Regiment Wisconsin on 11 May 1865

BIO>
Mendon Twp. -- Duane E. Grout, assistant agent for the C., M. & St. P. R. R., at
North McGregor, was born at Fox Lake, Dodge County, Wis., Feb. 22, 1846. His
parents, Stephen D. and Cordelia M. (Garrison) Grout, were natives of New York,
and had a family of three sons, viz.: Adelbert B., of Chicago; Irvin S., mining
in Colorado, and Duane E., who attended school until fifteen, when he enlisted
as a private in Company E, Twenty-ninth Wisconsin Infantry Volunteers, Sept. 27,
1862. He was in the battles of Port Gibson, Miss., siege of Vicksburg,
Fourteen Mile Creek, Champion Hill, siege of Jackson, Miss., Opelousas, La.,
Carion Crow Bayou, was in the "Texas Expedition," the battle of Sabine Cross-
roads, where he was captured May 8, 1863. He, with 100 others, escaped from the
stockade at Hempstead, Texas, Nov. 14, 1863, but was re-captured by some
Confederate cavalry in the Calcasien bottoms, La., and returned to Houston and
were exchanged at Galveston, Dec. 25, 1863. He then joined his company at New
Orleans, and took part in the Mobile expedition, Spanish Fort and Blakely. On
April 8, 1865, he was commissioned Second Lieutenant of the Fifty-third
Wisconsin Infantry Volunteers for meritorious service, and remained in the
service until the close of the war, when he was discharged at Madison, Wis. He
went thence to St. Louis, Mo., and clerked in a grocery store in the fall of
1867, when he went to Chicago and clerked in the spring of 1868, thence to
Woodman, Grant County, Wis., and took charge of a lumber yard for the firm of
Garrison and Co., until the fall of 1869. He was married there to Anna E.
Deitrich, on Dec. 5, 1869. She was a daughter of Daniel and Sarah (Geiser)
Deitrich. After his marriage Mr. Grout went to Dubuque for the lumber firm, and
in September, 1870, came to McGregor, where he began to break on the C., M. &
St. P.R.R., and was injured accidentally while coupling cars on July 11, 1870,
and since then has been employed in the office. He and wife have two children,
viz.: Herbert B. and Mary E. Mr. Grout is a member of A.O.U.W., Keystone
Lodge, No. 111 at McGregor. He was elected Mayor of North McGregor in 1880, and
is the present Secretary of the School Board. In politics he is rather
independent. History of Clayton County, Iowa, 1822 p. 983-984

I have his complete Military File from National Archives