Peter Warn Varn of Sweden and New York

Peter Warn was born about 1813 in Smaland, Sweden and died October 1888 in Caroll Township, Ivory, NY. His wife's name was Christina Johanson who was born August 1817 in Sweden and died July 1907 in Jamestown, NY. They arrived in the United States in the Spring of 1873 with their three younger children. Their older children arrived here before them.
I am not able to go any further back, do to not knowing who Peter's parents are.