Am I Canadian? - Could it really be this easy?

My GGGF (Great Great Grandfather) was born in Ontario and immigrated to the United States (Seattle, WA) in 1889 to help rebuild the city after the great fire. From what I can tell he naturalized in 1896. He was married to an American in 1980 and they had a child my GGF where my lineage begins. Given this am I Canadian? The application focuses on parents and mine have never lived in Canada, so if I am how do I go about applying?