Ok, it is a little confusing. In the NINTH Cav is listed WILLIAM L.
In the FIRST CAV is listed WESLEY P., also from Newton, close to Marshalltown in Company F:

From the roster of Company F:
Kimberly, Wesley P. Age 21. Residence Newton, nativity Iowa. Enlisted Feb. 18, 1864.
Mustered March 3, 1864. Mustered out Feb. 15, 1866, Austin, Texas.

The man from Marshalltown with a wife Emmaline and a daughter Ann Maude in 1910 is WESLEY C. He and Emmaline are also listed in the 1920 census, no sign of Ann Maude, who may have married.

WPA burial records for Marshall County Iowa show this WESLEY CLARK KIMBERLY:

KIMBERLY Wesley Clark born 1842 died 1933
buried Riverside Marshalltown Marshall

Note the difference in spelling Kimberley, and Kimberly