I have pretty detailed history of my family coming to Iowa County, Iowa, USA around 1854.  Now I'm looking to see if I can find any further information on the family in Wales.  I believe they came from Machynlleth.
David H. Jones (1811-1882) married Margaret M. Jones (1809-1872)  Both born in Wales.
Son - Edward H Jones (1852-1924) married Sarah M. Williams (1852-1940)
Richard Williams (1814-1860) married Ann Evans Pugh (1820-1885)  Both born in Wales
(Richard Williams founded Williamsburg, Iowa (1854)
Daughter - Sarah M. Williams (1852-1940)
Edward H. Jones was born in County of Powys, Jan 13, 1852 - on farm Rhyd'r Aderyn Cemmes.  
Sarah M. Williams was born in Williamsburg, Iowa, USA Nov. 3 1852
Any help you can provide would be greatly appreciated.