Looking for Cornelius Callihan Callahan of Rockingham CO VA and Knox and Morrow and Marion CO Ohio

Found Cornelius Callihan in Rockingham Co. Va. He moved to Knox Co. Ohio, then to Morrow Co. Ohio. He married Margaret Helphrey/Helfrey. One of their sons, Daniel Callahan married Mary (Polly) Queen; had a son Isaiah b. 1878 in Morrow Co. Ohio..Isaiah married Rachel Ann Reasoner . Daniel died sometime between 1900 and 1910 in Morrow or Marion Co. Ohio. His second wife, Hannah Queen Callihan, died in 1911, Marion Co. Ohio. Main thing working on now is Cornelius and his wife, Margaret - Where did they die? and where are they buried?