Trying to trace them back to Ireland and their immigration to the USA. They were married in Michigan and lived in MI,USA until they died. Catharine came from Co. Mayo, Ireland and her parents were Patrick Hughes and Catharine Doude.

There is a possible immigration for Martin via Philidelphia from Liverpool (Brig Jesse) but cannot be sure and also a known concentration of Langtons around Kilkenny, Ireland (that can be traced back to the Domesday book) but again I cannot find a link.
Thanks