Looking for Parents Siblings of Jasper Franklin Johnson of Oklahoma

I am looking for parents/granparents/siblings of Jasper Franklin Johnson of Oklahoma. The 1880 Federal Census states he was born in Georgia. In that year he was living in Montague, Texas. The 1900 census shows him living in Township 21, Cherokee Nation, Indian Territory. He was married to Margaret P. Steel. The had the following children: William Walter Johnson, Mary Ellen Johnson, Martha Johnson, Joseph Johnson, Tommy Overstreet Johnson (my grandfather, who was married to Nellie Frances Broadston). Jasper, Tommy Overstreet and Nellie are buried in Bridgeport, Oklahoma. Any information on Jasper, Margaret and any of the children would be greatly appreciated.