According to "The Farmers Advocate" atlas of Caldwell co., MO 1897 (of which I have a copy) it was so named for John Caldwell, Indian scout. If you would like more information on Caldwell co., I would be happy to try to answer your questions. This book has maps of each of the towns and lists of the people who owned land there at that time. There is another URL that I have copied things from at different times that has the history of the beginning of Caldwell. But the URL escapes me at the moment, I will try to find it.