If you have to claim and re-check baggage at DFW, I very much doubt that arriving at DFW one hour before your JL flight departs will work. Have you checked the baggage check-in deadline for JL at DFW?

Many people advise that, when taking a separate "positioning" flight before a long-haul flight, you plan to arrive at the intermediate city a day before, in order to give yourself more of a cushion in the event of IROPS. Is your AA CMH-DFW flight available with Avios on the preceding day?