At first I was confused on which Frank Clendenin until I looked up his pension files. In his file wife is Mary A. Clendenin and all the pieces went together.

Frank Clendeinin: Death Date 8-17-1906

Enlisted Aug. 18, 1861
2nd Ill. Cav Co. A
Bugler

Transfered to:
8th Cav
Mustered out:
Oct. 14,1862 as Chief Bugler

Then I found him:
147th Co. B. Ill. infantry reg.
Enlisted July 2, 1865 ?????? Jan maybe?
Private
Promoted:
Full Capt. Feb. 18, 1865
Promoted:
Full Major July 13, 1865
Mustered Out Full Major Jan. 24, 1866

Sources: Illinois: Roster of Officers and Enlisted Men

I will try to find other information for you. Whiteside Co. is just across the river from me and Morrison is about 20 miles away. Oregon and Morrison are less then 50 miles from each other. I will look in the newspapers here and also in Morrison to see what I can find. Morrison does have a museum and I have friends that volunteer to work in the museum. When I find something I will let you know. If you would like anything like Obits, wills, grave, articles. I will look to see if any living family still lives around here.

Nancy F.
23rd Tn Co. E
Historian