As I mentioned, my great grandfather, Thomas William Unthank was born March 26, 1874 in Garforth, Yorkshire, England.I have verified this via the following 1881 British Census and it would appear that your Issac is my g-grandfathers Uncle.
Abram UNTHANK Head M Male 61 Ferrybridge, York, England Coal Miner
Sarah Ann (Hewitt) UNTHANK Wife M Female 53 Castleford, York, England Coal Miner Wife
James UNTHANK Brother W Male 73 Ferrybridge, York, England
Isaac UNTHANK Son U Male 19 Micklefield, York, England Coal Miner
Hannah UNTHANK Daur Female 11 Garforth, York, England Scholar
Thomas UNTHANK Grandson Male 7 Garforth, York, England Scholar
George UNTHANK Grandson Male 5 Garforth, York, England Scholar
Fred PRIVAL Son In Law M Male 19 Barwick In Elmet, York, England Ostler Groom
Ann PRIVAL Daur M Female 18 Micklefield, York, England Ostler Groom Wife
Thomas immigrated to the US in 1886 at the age of 11 ( I don't know if he traveled alone or with anyone, I am still looking for an immigration record).
Thomas's father, Abraham Unthank (born July 23, 1853) died in Springfield, Illinois on May 10, 1933.I am still looking for an immigration record on him.
There is a public member tree on Ancestry.com called "Unthank Family Tree" that lists Sara's father as a William Hewitt (1795 - ) and Abraham's parents as Jonathan Unthank (1780 - ) and Elizabeth Robinson (1787 - ). The 1851 census has a son William born about 1844 so it looks like Abraham and Sara were married by at least 1844.
I have the following on Isaac. Issac was born 02 Jul 1862 in England and died 18 Nov 1931 at Eldorado, Saline, Illinois, USA.
Issac Unthank married a Anna Marie Starkey 23 Aug 1886 at La Salle, Illinois, their son John married a Bessie Reeder 01 Nov 1927 at Texas City, IL. and their son Don married Shirley Butler.