I know that the Carolinas got a lot of highland Scots settlers after the Jacobite rebellion, Bonny Prince Charlie and all that. There were even newspapers printed in Gaelic in the Carolinas for some time after the mid 18th century. I don't know if the Scots got as far as Mississippi though.
The Carolinas also got a lot of Scots from western New York and Pennsylvania during the French and Indian War. There are Presbyterian churches across the Carolinas that were founded in the middle 1700s. One such near Charlotte is Coddle Creek Associate Reformed Presbyterian Church which celebrated its 265th anniversary last year. And, yes, "Missippi" has quite a goodly number of Scots. Most of the originals came from the Carolinas to settle land-grants received as their pay for service in the Revolutionary War. I've been asked to preach at Philadelphus Presbyterian Church in rural Wayne County, Mississippi, late in the Summer for its annual home-coming service. Its fellowship hall, which is constructed from logs salvaged from the congregation's first church building built in the late 1700s is called "Scotland Hall."
