Osmund Tveito Tollefson

Osmund Tveito Tollefson (b. 19 July 1844 in Vinje Telemark Norway). I'd like to find records of when he left Norway, ship manifest, and when he came to America. It's possible he emigrated in 1861 and his daughter thought he was on the ship William Tell. I don't see this ship, but there is a Wilhelm Tell. His confirmation record shows he was still in Norway on 8 July 1860 (https://media.digitalarkivet.no/en/view/1422/9311/64 line 2) and I believe he was in America in the 1865 US Census. A family story is that someone in America paid him to take their place fighting in the US Civil War. Was this a common reason to emigrate to America? I haven't been able to find a record that he fought in that war, but his name is misspelled a lot in historical records. Thank you!