Being a Welshman and while listening in on a local radio show they just so happened to be interviewing an African American professor and an expert on African American surnames, and what he said made things that I always questioned make sense at last, now I have always wondered why the vast majority of African American's have Welsh surnames? such as Williams, Jones, Lewis, Griffiths, Evans, Davies, well the Professor said that these were the most common surnames for African American's simply because a greater number of plantation owners happened to be of Welsh Heritage then it was custom what ever slave you had on the plantation they automatically took the surname of the plantation owners, a simple but interesting fact but this always made me scratch my head wondering why? Mystery solved. PS, my Welsh surname is Pugh, but through the centuries it's been change because at one stage it would have probably looked something like this ap Hugh, the ap means Son, just as Mc in Scottish and O in Irish Gaelic also means Son of.
http://en.wikipedia.org/wiki/Welsh_surnames
Jamie.