Will or guardianship or adoption in Highland Co. Ohio

My ancestor Daniel Williams appears on the 1850 census with his wife, Rebecca and children and a grandson John Williams, age 5, without his parents (my ancestor). John's parents were Amos Addison Williams (went by Addison I think) and Margaret Noble. I am searching for a will (Daniel died 4/29/1882, Rebecca died 8/1851 to prove that Amos or Addison was their son; Amos or Addison disappeared and is found in Georgia and died in Andersonville Rebel prison during the Civil War I think. The grandson John Williams appears in 1860 in Illinois with an aunt and uncle. Daniel did remarryEleanor Ellen Bolin who outlived him. I would appreciate any help or look ups on this group of the family. Linda Cunningham