The IC/CN Memphis-New Orleans main line is at Marks a few miles east. My MS map shows three MSOR lines at Clarksdale, but I suspect they see little activity. Vaughn is well south on line between Memphis and Canton. The north end of this is active to at least Grenada, which has a large old brick depot, while the south end is inactive last I knew. There is nothing but the track left at Vaughn.
The Casey Jones Museum is in the old IC depot at Water Valley, which was Jones's home terminal when he died. It has some neat stuff and some junk. Check the internet for days and times it is open. I would call ahead to assure someone will be there as it is a one or two man labor of love place.