Written just after the passing of the 1924 Immigration Act, this book by one of America's most prominent racial thinkers is an in-depth analysis of the racial developments which led to the American Revolution, the Civil War and the mass immigration of the late nineteenth century which disrupted the until-then almost entirely North-Western European colonization of North America. Delighted that the 1924 law effectively stopped all further mass migration, Stoddard devoted the rest of this work to discussing solutions to what he called the existing "racial dilemmas" facing America, namely the threat of illegal Mexican immigration, the growth in black numbers and unassimilable European immigrants. Although the 1924 act was repealed in the 1960s, this book contains many observations on race and the implications of mass migration which are more applicable than ever before.