Nelson/Simpson of Massachusetts

I've been attempting to locate some information on my great grandfather and great grandmother who were both born in Norway and emigrated to the US (date unknown). Ingwald Simpson b. 1879 in Norway d. 1927 in Concord, MA Martha Nelson b. 1879 in Norway d. 25 Jun 1951 in Concord, MA Martha had 3 brothers (Claude b. 1882, Nick b. 1886 and Martin b. 1892). Any information would be greatly appreciated. Thank you, Arthur Floyde