"... I have some Poethigs who came to America around 1880. A very nice man named Richard Poethig contacted me one day and we think we are related but don't know how. His people were in Milwaukee around the same time as mine ..."
There's a newer resource in Milwaukee that may help with your research: "Milwaukee's German Newspapers; an index of death notices and related items" (1844-1950). There are about 30 Poethig entries or references in the index.
Gary Rebholz, compiler/editor
Indexing Milwaukee's German newspapers continuously since 2007 ...