Hi Sue :0) Isn't it interesting how the surname DERRY has taken so many paths? I believe we are all correct in our synopsis. Having heard the English version of the origin of the name DERRY in past years (that is your description as well), I believe the name has its' origins in all three countries. While spelling variations are many, the name holds much in the way of its' history. As the Irish say, it is not an Irish surname, so goes the Germans, yet, JACOB DIERY sailed from Germany in 1752 to America with his wife and five children. Finding the surname DIERY, in Germany, is as about as rare as DERRY in Ireland. While there are some in Germany with the name spelled DIERY, there are few.... and, while he sailed from Germany in 1752, it does not mean he was German. It is simply where he sailed from. He did change the spelling to DERRY once here in America. I have often wondered, was his name really spelled DERRY, and the name mis-spelled by those taking and writing down names when they boarded the ship? Hard to say.
This discussion thread, however, has been grand! I believe this a wonderful way for us searchers to come to know one another a little better, and understand where we are in terms of our search for our ancestors.
We may, one day, discover we are all related to a single line of DERRY. Maybe not, but it is still fun, and I love meeting other Derry's.
Regardless of its' origins, the DERRY family has a rich history in America, and its' delvelopment as a free nation. I am proud to be their son. God Bless America!