Two verifiable soldiers of the 2nd MO Cav - Merrills Horse (USA) that were Enlisted at Cincinnati, Ohio on Sept 5, 1861 and Mustered-In at St. Louis on Sept 9, 1861 in Company C were:

Matthew Itstein
Henry Cook (Krukawith)

Both of these soldiers were killed at the Battle of Kirksville

Another source of the activities of Merrills Horse is The Munger Family Civil War Letters at the Butler Center for Arkansas Studies:
http://arstudies.contentdm.oclc.org/cdm/compoundobject/collection/findingaids/id/5348/rec/1