Ford Butler's two children are listed in the 1880 Census as being born in Mississippi during the war. Rootsweb lists the daughter as being born in Ellisville, MS which is in Jones County. While I don't always believe everything I read on Rootsweb and it definitely needs to be verified, this would make sense. Jones County had a couple companies in the 7th and it's right next to Clarke County....

One thing that has always kind of confused me about Louis F. Butler is that he's listed in the 7th Battn (at least I think it's him, can't find anyone else with his name) but his brothers (the ones that I can identify) are all in the 8th Regiment, Co. H which is a Lauderdale County company...