Emanuel Jesse Green born March 10, 1887 in Ripley MS, and living near Kossuth in 1917, married (no wife's name) and a child. Described as tall, slender, blue-eyed and dark hair. WWI Draft Registration Card That's the right age and location to be a son of John and Sarah, but it doesn't identify his parents.
And here he is in 1920, living in Kossuth, Alcorn, Mississippi, United States, married to Birdie Green, with son Emanuel and daughter Alwin: 1920 US Census Parents still not identified.
His Find A Grave Memorial does assert that John and Sarah were his parents, but no source is given. There are a number of names for further research which might prove beneficial.