Try this listing at the Missouri S.O.S. Archives.
Name: COLDERON, JENNINGS I.
Conflict: Civil War
Type of Unit: Cavalry
Organization: Missouri Volunteers
Name of Unit: 16th Regiment Cavalry Volunteers
Alternate Unit Name:
Period of Service:
Record Group: Office of Adjutant General
Series Title: Record of Service Card, Civil War, 1861-1865
Also see this listing.