My older sister is the genealogist in the family. On my dad's side they came from the state of Baden in 1847, when there was quite a bit of social and political unrest in that region. Germany did not exist until 1871, so they were from Baden.
My ancestors from Hessen came to the United States in the 1860s, so that makes sense. I have ancestors on my mother's side of the family that came from Baden-Wurttenburg during the eighteenth century. However, I believe that these ancestors were Huguenots, which technically makes them displaced French Calvinists.
Another thing that is interesting about German migration is that the early Germans were mostly protestant (Maryland and Pennsylvania where the only colonies were freedom to practice any religion was the rule). The Catholic Germans did not start showing up in large numbers until after the United States was a country. Western Maryland was mostly settled by Germans from the Rhineland-Palatinate and Baden-Wurttemburg in eighteenth century. From what I can ascertain, Pennsylvania Dutch (a.k.a. Pennsylvania German) is rooted in the dialect spoken in the Rhineland-Palatinate and Baden-Wurttemburg. This language is still spoken by the Amish.