I have been researching my husbands family. Jacob Hermann was born April 15, 1804. His wife was Anna Marie Negans or Gans. They were in US by 1839 when their son was born in US. On US census records in 1870 they listed their homes as Prussia / Nassau and Darmstadt for Anna Marie. I recently got immigration papers below from a relative. Some folks on the message boards said it showed he lived in Eams - now called Bad Ems. I found information that this is in Rheinland-Pfalz. I have attached pictures of the paperwork.

The family is Catholic. I would like to find information on Jacob Hermann. I am also hoping to find marriage record which I understand is usually where the bride lives but am not sure if Darmstadt is in this area.

Any ideas on where I should look or how to go about finding this information.
Thank you.