Finding William Grimm in German Records

HaJeonPuleum

I have just started genealogy on a friend's family tree but just happened to run into a dead end already. The ancestor's name is Wilhelm Grimm (His english name was William). He was born around 1844 in "Hanover", Germany, likely to be Hannover, Niedersachsen. He married Louise Schneekloth, daughter of immigrants. He later dissapeared after leaving his home in Nebraska, and reappeared in Chicago.