A reprint of a 1920 classic surveying the world racial situation after World War I and warning of the coming non-White population explosion. "The world-wide struggle between the primary races of mankind...bids fair to be the fundamental problem of the 20th century, and...perhaps the future." Lothrop Stoddard was regarded as an expert on demographics in his day. Stoddard's arguments were once taken seriously by the American establishment and President Warren G. Harding publicly praised this book at a public speech on 26 October 1922. The introduction to this book was written by Madison Grant, Chairman of the New York Zoological Society, and Trustee of the American Museum of Natural History. A Harvard Ph.D in history, Lothrop Stoddard was the author of The Revolt Against Civilization, The French Revolution in San Domingo, and other works that played a key role in the enactment of America's 1924 immigration act. Margaret Sanger appointed Lothrop Stoddard as a board member of the Birth Control League (the forerunner of Planned Parenthood). This work is important original source material for historians and scholarly researchers.