Thank you for your posting.I only have a few minutes to answer now, I will get back to you again later when I have time to look at my files.
But as clarification for the sake of others viewing this posting, a correction for your Generation 1 data.
His name was Roburtus Mansfield Copeland, although he had a son (brother to John G. A. Copeland) who was named Roburtus Marion Copeland - in secondary information Roburtus' name can be verified by looking at "A History of Stewart County, GA, Vol I" which you probably can access more easily than the Family Bible or perhaps his Gonzales County, TX death certificate, or his tombstone, which listed him as R. M. Copeland.Neither he nor his son were named 'Marion R.' Copeland.
1870 Census, Pike County AL page 24 beat 721 July 1870: #195/195 Copeland, Roburtus 43, farmer, value real estate 1000, personal property 450, GA. Sarah 37 f GA John 20 m GA William 18 m GA Richard 16 m AL Cornelia 13 f GA Earley 11 m GA Connie 9 f GA Roburtus 6 m GA Lula 4 f GA Mattie 9/12 f AL
In the mid 1870s, they moved to Gonzales County, TX where at least two sons, John G. A. and William Alphaeus Copeland already had been.