Several problems in trying to establish parentage of Richard and Sarah
You don't know for certain that the marriage I posted is the correct one
Even if it is - Morgan is a common Welsh (and English) surname and without knowing when and where Sarah was born it would be impossible to the find the correct information
Same problem with Richard - no details of when or where he was born
Re: James. In your opening post you say that
He came to America approx. 1830.
The obit above confirms he came with his parents so if you find their deaths you may get additional info