I am a Morgan decendent, and was looking for info on the Morgans, when I was looking in the Sumner Co. Tn area and came across the Brights, who as you know married into the Morgans. You might want to take a look at this info as it comes from a Bright great grandson, James R Bright of Nashville Tn. I found this information re; the Morgans very acurate, so I would puta lot of confidence in the Bright info too.
The address is : www.rootsweb.com/~tnsumner/index.htm
Look in the "Biographies, Descendancy Charts, and Pedigrees" and The Bright Family of Tn.
This info list James Bright Sr.'s wife as Margaret Dinges. (mother of James Bright that married Nancy Morgan, daughter of Capt. John Morgan and Mary Hall)