Madison Grant was an American writer and zoologist known primarily for his work as a eugenicist. The subtitle of the book refers to the key theory promoted by Grant – the superiority of Nordic race and its responsibility for human development. Theodore Lothrop Stoddard was an American historian, a member of the Ku Klux Klan, and author of several books which advocated eugenics and scientific racism. His strategy to frighten readers with the spectre of a race war, by presenting the enemies of the 'white race' as being strong enough to pose an existential threat, but weak enough to defeat, is still being practiced, some hundred years later, by white supremacists. James Woodsworth’s book served as a blueprint for Canada’s 'Immigration Act' enacted soon after the publication of the book. In this book, Woodsworth provides a hierarchy of races and ethnicities based on their ability to assimilate into Canadian society. Those belonging to 'prohibited classes' were deported and denied entry to Canada.