Can anyone tell me anything about a Capt. Senn? This is what I know...

Uncle Joe enlisted in the 19th SC Infantry [When] November 18, 1862 [Where] Chester Dist. [By whom] Capt. Senn.

The only references I have found are entries on several SC unit lists as "Capt. Senn's Post Guard". One entry is followed by "[Infantry]".

Ancestry.com gives data for a Captain R.D. Senn...
Side: Confederate
Regiment name: Capt. Senn's Company, Post Guard, South Carolina
Regiment name expanded: Senn's Company, South Carolina Post Guard

What is a 'Post Guard' unit?

I'd appreciate any insight anyone might have on this!!!

Sharon
Jemison AL