The New York Times has an article on the resurgence of interest in Gaelic in Christmas Island, Nova Scotia. (You’ll likely have to register to read it). As the article makes clear, the earlier Scottish settlers of Nova Scotia, and their descendents, commonly spoke Gaelic until after World War 1.
My first Gaelic book, a present in my early teens, was a “teach yourself” pamphlet with cassette tapes that came from Nova Scotia. Today there’s a wide variety of Nova Scotia Gaelic and Celtic cultural resources on the net, starting with the Gaelic Council of Nova Scotia. And there’s still Gaelic and Celtic culture elsewhere, for instance, Cape Breton’s Gaelic College. Fortunately there are already some attempts to preserve and continue Gaelic culture, particularly the music. The Library of Congress for instance has made available recordings and transcripts of Gaelic songs sung by Mary McDonald in 1931. And in Iona, Nova Scotia, ther’s the Highland Museum, a “living culture” museum that celbrates and preserves Gaelic culture in Nova Scotia.