sharonks on Family Tree Circles

My great grandfather, John Reuben(Rubin)WHITSON b. Dec. 1849 in Iowa.
Married Martha E L COLEMAN in March 1889 in St Joseph, Buchanan, MO.
I have been unable to find anything about him between 1849 and his marriage. They had 2 children, George and John Jr. In 1900 I have record of them living here:
Township 11, Creek Nation, Indian Territory. John Sr. died in 1911, not sure where though.

John Jr. b.Dec. 1889 married Mary Ellen GRANTHAM in 1914 in Fort Smith District, Arkansas.In 1920 and 1930 I have evidence of their family living in LeFlore County, OK. They had 6 living children, of which one was my mom. Ovie Marie Whitson b.1922 OK.
John Jr. died in Bakersfield, Kern, CA in 1974.

I am trying to find something about the parents of John Sr. Have been working on him for several months, all leads I thought I had became dead ends. Appreciate any help at all. Thanks