"Can anyone offer suggestions how to learn more about German-American periodicals? My primary area of interest is along the northern immigration trail.... New York, Penn, Ohio. My ancestors settled in southwest Michigan. I would like to research periodicals from these areas in the mid to late 1800's. Ideas?"
Use online library catalogs in your key cities and figure out how they have set up their subject search. There can be a big difference between what an academic writes about on the history of a given publisher and what remains extant in library collections.
"Milwaukee's German Newspapers; an index of death notices and related items" (1844-1950).
Gary Rebholz, compiler/editor
An original, independent, ongoing project started in 2007.