Hi David, it appears that there are two "strains" of Artleys; German and English. We (both of our family lines) are the German "strain" for lack of a better word.
Our common ancestor was John Heinrich Erdle, b. abt. 1737 and d=1795, PA. Erdle was the family name that was Americanized to Artley in later generations. This branch came from Germany, settled in Pennsylvania and then slowly spread throughout the U.S.
The English Artleys originated in England and seemed to mainly have settled in Michigan. I've heard a theory that if someone was to do the research in England, they'd probably find they were originally Erdles from Germany but I don't know. I've got too many holes in the lineage in America to start searching in Europe at this time.
My father W. Russell Artley who was born in Ohio, lived there and Indiana and moved to Washington state during the 30's, only knew that his family was Pennsylvania Dutch. After he died in 1992 I did the research.
I've compiled quite the database so if you have any other Artley questions, I'd be glad to answer them. Send me an email.