I did eventually trace my uncles family to Texas,his grandson was there but did not want contact,sad but everyone has a choice.
I have a large family tree on the internet anyone who wishes to look,all Uk Hickmans.
http://www.tribalpages.co./tribes/j111048

I have comments on meaning of the name Hickman,Hick as I understood it was a diminutive of Richard,hence meaning,servant of Richard.
also the Irish Hickmans I think descended from Oliver Cromwell times, English Hickmans who were given land in Ireland by Oliver Cromwell,he did this for quite a few English,pushing the Irish of their lands.
Joyce