Thanks for all of the great advice.
For various reasons, the trip didn't happen this year, but it is most definitely on my list for another year, perhaps 2020. When I do it, the current plan would be to take the train from Chicago to NOLA, follow the ACA Great Rivers South route to IL where I would pick up the TransAmerica for a short bit and take the train home from Carbondale, IL I might just keep riding through IN to home, but that might be outside my time limit.