Ohio River Pottery ID Needed

On a recent mudlark on the Ohio River I found a couple pieces of what appears to be old pottery.
I could not identify either the texture, color or maker from any resource on the internet.
I was wondering if you may be able to help identify who made it and what it was used for.

The shard with the stamp is roughly 4" x 5" and is very thick and heavy.
The outer color (glaze?) is brown/beige, the inner (clay?) is dark.
There is a circle/stamp on the outside with what appears to be 3 lines of writing inside
The first line is written in English letters from left to right in an arc moving up to the right and ends with an "S" near line at the 2 o'clock position
The next line is indistinguishable but looks like "F. of L."
The bottom line definitely ends in "C_SVILLE. O."; could be CASVILLE or CHSVILLE.

Looks like a piece of old drain or sewer pipe. May be best to visit a reclamation yard, if you have any locally, to see if they have any whole ones with complete marks

I notice that there's a town called Lucasville Ohio. Might be worth checking if there was at one time a brickworks there which made fireclay drain pipes.