The impossibility of any advanced and prosperous community maintaining its social standards and handing them down to its posterity in these days of cheap and rapid transportation except by restrictions upon immigrations is thus explained by Professor Ross: "Now that cheap travel stirs the social deeps and far-beckoning opportunity fills the steerage, immigration becomes ever more serious to the people that hopes to rid itself at least of slums, 'masses,' and 'submerged.' What is the good of practising prudence in the family if hungry strangers may crowd in and occupy at the banquet table of life the places reserved for its children? Shall it, in order to relieve the teeming lands of their unemployed, abide in the pit of wolfish competition and renounce the fair prospect of growth in suavity, comfort, and refinement? If not, then the low-pressure society must not only slam its doors upon the indraft, but must double-lock them with forts and iron-clads, lest they be burst open by assault from some quarter where 'cannon food' is cheap."[153] These admirable summaries of the immigration problem in its world-aspect are strikingly illustrated by our own country, which may be considered as the leading, if not the "horrible," example. Probably few persons fully appreciate what magnificent racial treasures America possessed at the beginning of the nineteenth century. The colonial stock was perhaps the finest that nature had evolved since the classic Greeks. It was the very pick of the Nordics of the British Isles and adjacent regions of the European continent--picked at a time when those countries were more Nordic than now, since the industrial revolution had not yet begun and the consequent resurgence of the Mediterranean and Alpine elements had not taken place. The immigrants of colonial times were largely exiles for conscience's sake, while the very process of migration was so difficult and hazardous that only persons of courage, initiative, and strong will-power would voluntarily face the long voyage overseas to a life of struggle in an untamed wilderness haunted by ferocious savages. Thus the entire process of colonial settlement was one continuous, drastic cycle of eugenic selection. Only the racially fit ordinarily came, while the few unfit who did come were mostly weeded out by the exacting requirements of early American life.