I have found information that I believe is your Graham-Gibson line.
The name Marcillus gave some trouble, no doubt. I found their marriage:Lilas “Grayham” married Rosa B. Gibson 10 October 1894, in Lincoln Co. OK.
Although Oklahoma began keeping death records in 1908, it was not mandatory to file until several years later.So finding a death certificate as early as 1913 (the death year of Rosabell Gibson Graham) would be hit or miss.My father’s first wife died in 1915 in Lincoln Co. OK.We have her information, but the state could not find a record of her death on file.
In looking for the “right” family I try to determine if other siblings also came to Oklahoma, and in using that criteria I feel sure that the following is your Gibson line.
1880 Crawford Co. AR, there are 5 siblings living together with the oldest listed as Head of the Household.All were born in AR, father born in Indiana, mother b. in Missouri.Apparently the parents were dead by 1880.
Francis (male) Gipson (Gibson) age 20 Henry, 18 Josie, 15 Hattie, 12 Rosabell, 9 Elizabet, 5.
Although birth records indicate parents were living in 1870, I could not find the family in that census.However:
1860 Cove Creek Twp, Washington Co. AR John Gibson, 30, b. IN Sarah, 22, b. Mo Clementine, 3, AR Francis (male) 7 mos. b. AR James Askins, 21, b. MO, farm laborer.(Sarah’s brother) I have also seen the name as Atkins and Adkins.
From Arkansas Marriages, John Gibson, b. 1830, married Sarah Adkins, b. 1838.They were married 25 Feb 1855 in Washington Co. AR
Rosabell’s oldest sister, Clementine “Clemmie” Gibson married Loftis Elliott Henry, 31 March 1876, Washington Co. AR.She was widowed before 1900.By the 1910 U. S. Census she was living in Lincoln Co. OK.She and her husband are both buried in Stroud Cemetery, Lincoln Co. OK.
Rosabell’s brother, Henry (William Henry) Gibson was in Lincoln Co. at the time of the 1910 census, but I lose him after that.It is a very common name.
Her brother, Francis (Francis Marion Gibson) remained in Arkansas, living in Scott Co.Here is a link to his record at findagrave.It identifies his parents as John Gibson and Sarah Atkins.He named a daughter Rosa.
In 1910, Joseph Graham, father of Marcillus Graham, was living with Marcillus and Rosabell in Lincoln Co. OK.Joseph and his wife “Millie” were in the Creek Nation in 1900.Joseph Graham was born about 1826 in Kentucky.He is buried in the Stroud cemetery, Lincoln Co.His stone is the same design as that of Marcillus and Rosabell Graham.I have not found the burial record for Millie Graham.
I hope you find this helpful in furthering your family lines research.