Peter Halvorsen in Telemark, Norway

I am looking to find who Peter Halvorsen married. Peter Halvorsen Born - 23 June 1811 Mo, Telemark, Norway Died - 21 Sept 1885 Houston, Houston, Minnesota Parents Halvor Petersen Birgithe Olsdatter Peter Halvorsen immigrated to the United States, I don't know when. In 1880 it says he was widowed. He had two sons that I know of. Swan Peterson Born 10 Oct 1836 in Norway John Peterson Born in 1846 in Norway Thanks Cory