Hi ~ since writing the initial post here, I have learned that my Zaug family line comes from various towns in Alsace including Ottrott, Klingenthal, Obernai and Selenstadt.
The area has indeed changed between Germany and France several times. Some of the family changed their name to Zang when they came to America. My gggrandmother told my aunt that her grandparents were from Switzerland. I have traced my direct Zaug line back to the late 1700's.
If you provide me with more information, perhaps I can supply you with some info.