On my ancestor Victor Robin's civil war pension document it says for service:
G 1st Mo. Inf
K 2nd U.S.R.C. Mo. Inf.

The date for his application was Dec 11, 1890 and then his widow Francis applied Aug 22, 1901 after his death.

This may sound like a stupid question, but can anyone tell me what the above stands for and where I might find out more info about it and his service?

Thank you
Patty