Source Records

Hello Carroll co Researchers,

Am looking for records of:

James Thomas (a shoemaker and served as a sherif)who lived in Carroll county, Arkansas
between
1854 and 1866-67.

His census material confirms his residence.
1860 Mountain Spring, Carroll, Ark.

I've been told that this area became a part of Boone county and Marion county?

My question is:Where would be the best place to start looking for the early county records for this area?

Thanks so much for your time and HELP!!

Lynn