Here are two possible leads:

Alexander Hamilton Dunn (1838-1920)
Find a Grave Memorial 24802937
Born in Mar 1838 and died in 14 Jun 1920 Evansville, Arkansas
No other information

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Alexander H. Dunn

Residence Ashley IL; a 23 year-old Carpenter.
Enlisted on 6/25/1861 at Caseyville, IL as a Corporal.
On 6/25/1861 he mustered into "C" Co. IL 22nd Infantry
He was transferred out on 8/19/1863
On 8/19/1863 he transferred into Veteran Reserve Corps "Not Stated"
He was discharged (date not stated)
Promotions:
* Sergt 2/1/1862
* 1st Sergt 11/1/1862
He was described at enlistment as:
6' 0.5", light complexion, gray eyes, dark hair
Other Information:
born in York, Canada

Sources used by Historical Data Systems, Inc.:
- Illinois: Roster of Officers and Enlisted Men
- Illinois State Archives @ http://www.ilsos.gov/isaveterans/civilmustersrch.jsp
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