dual from grandparents

I am trying to gather information on immigration to the us from Canada. My family originated from the us in the 40's, neither great grandparent giving up their us citizenship, and as far as I know my great grandmother never took canadian citizenship (???) I have been told and read that grandchildren are eligable for citizenship based on right of blood. I can prove with birth certificates and marriage licences the geneological link. There is also suspected link to D.A.R through my Great grandmothers side. My grandfather was not born in the us but half of his siblings were.

My great grandparent's information is as follows:

My great grandmother: Born in Edmunds North Dakota in 1905
Her mother: born keokuk in 1878 buried Pingree North Dakota
Her father: Immigrated to the us from scotland in 1875 married my great great grandmother in 1895
Her mothers mother: born 1842 -d 1907 Pennsylvania
Her mothers father: born 1843 Pennsylvania

I can provide more information if needed


My Great grandfathers information: Born in Constanta Romania 1902

immigrated with his parents as a small child, both parents died shortly after comming to the USA was raised by his uncle in the southern states, not much information is available but can be located.

Any information would be greatly appreciated or recommendations to people I should be talking to.

Invest in speaking to an immigration lawyer specializing in Citizenship cases. Contact AILA for recommendations.