Joel, My husband's line has Easons from Cobb too. In the Virtual Vault at the State Archives on line is a death certificate for Minnie Beatrice Eason Buckner b. 1-1883 and who died on 7-22-1924. She was the daughter of M. Eason and Sarah Smith Eason and all were born in GA.Beatrice died in Smyrna. I'm not sure who M. Eason was, but found Beatrice on the 1900 Douglas Co., GA Census with N.M. Eason and wife Sarah.
My husband's great granddad was Isaac Burke Eason b.1856 who had a brother named Nathan or Nathaniel. The TYPED 1880 Census lists him as Nathan S. I have not looked at the microfilm of the original. Nathan S was listed as brother to Obediah R. Eason. Other census have Isaac, Nathan and Obediah in the same household. They were sons of Raspberry Eason who was from Fayette Co., GA. I have been told that the Fayette Co. Historical Society has info on the Easons.
My opinion is that your Nathan M could be Nathan S. Eason who lived in Powder Springs in Cobb and just over the county line in Paulding Co, GA. I don't have anything that is a direct connection, except that the locations are so close. Many families in Cobb had connections to families in Douglas and Paulding Co.
I would love to hear back from you, especially if you think that there is a connection.
Husband's line is Obediah R. Eason>Isaac Burke Eason>Minni Ella Eason m. Joseph Alonzo Cheek>husband's grandmother.