You can start your search for Scandinavian ancestors by first gathering all the information possible in the US for their descendants - taking that info and working back to reach those who actually emigrated from Norway and Sweden.
http://www.rootsweb.ancestry.com/~wgnorway/good-queries.htmA quick look at the free databases on Familysearch.org told me that Richard was born in New York, Agnes in Sweden. That was the 1940 US census -- you'll need to find MORE. Perhaps Agnes entered the US through Ellis Island and that would be another good place to search for more detail information on her.