Karl,
If you go to the following site and look up Wittenberg, you will find three
to choose from in different parts of Germany, as well as many other
variations.
http://www.jewishgen.org/ShtetlSeeker/LocTown.asp
Since the information came from a US Census, the spelling is suspect. THe
correct location could also have been "Württemberg" which, at one time, was
a province (state) in what is now known as Germany. It was part of what is
now Baden-Württemberg. I have observed "Württemberg" or "Wuerttemberg" on
US Census.
Hope that helps a little.
Dave Thies