The George W. Chapman I have may be a name given from your ancestor. Mine was born in 1854 brother to Lewis which is my great great grandfather. I have traced Hiram George's father to Vinton County, Ohio but I cannot get further.

George W. Chapman 11/8/1854 d. 1918.
I have George's death certificate - on it he was
buried in Jacksonville Ohio,( I have another document
that states he was buried in Elk Cem in McArthur,
Ohio) signed by Mrs Lena Hipscher from Jacksonville.
His residence was in Jacksonville and he died in
Grant Hospital Columbus, Ohio.

CHAPMAN G W
County Name: FRANKLIN Date of Death: 7/17/1918
Volume Number: 2636 Certificate Number: 42582

Lewis Marion Chapman (my line) m. Mary Elizabeth
Souders 1/2/1865 she was b. 12/15/1847 and died
11/25/1917 Mary had 3 brothers and 2 sisters.
Eli,David,Sarah (othernames not known). She was the
daughter of William and Elizabeth Ann (Wilson ) Souders.
Lewis died 8/18/1927 at Zaleski Oh, Vinton County.
( I have his death certificate - on it it says
he was born in Licking County - but I cannot find him
or Hiram in the census from that county). his daughter
Annie Ansel signed the certificate.