thorvald christian tønnessen in USA

Hi! I'm trying to figure out what happened to my great- great grandfather, Thorvald Christian Tønnessen. https://familysearch.org/pal:/MM9.1.2/MJH2-TPB/p1 He went to America the same year as my great grandmother was born and then suddently broke of all contact with his wife and daughters in Norway. I found information about an naturalization petition in 1896 and also managed to locate a picture of the petition on the internet. The name and birth date on the petition fits perfectly. https://familysearch.org/pal:/MM9.1.2/SMV2-C6T/p1 Does anyone know how, or where, I can possibly find more information about this? There are stories of him possibly finding a new wife so we are interested in finding out what happend to him after he applied for american citizenship. Any information would be appreciated! Mari