

Canada has citizenship by descent from a Canadian citizen and the rules were recently loosened so tons of Americans are applying to prove their descent from a Canadian citizen: https://www.canada.ca/en/immigration-refugees-citizenship/services/canadian-citizenship/act-changes/rules-2025.html
Last I checked, the processing time for all those applications was 33 months because so many people were applying.











According to this it seems that it’s transitive so it goes back all the way to the 1600’s as long as they were a Canadian citizen or (before either 1947 or 1949, depending on province) a British subject living in Canada.