PREFACE TO FIRST EDITION 
xxiii 
The Immigration Problem is one of vital interest 
to the American people. President Roosevelt said 
that he considered it, with the possible exception of 
that of the conservation of the natural resources of 
the country, our most important problem. Upon our 
policy in dealing with the immigrants depend, to a 
very noteworthy extent, the progress and nature of 
the development of the nation economically, politi 
cally, and socially. 
Heretofore the discussions on the subject of Immi 
gration have of necessity been based very largely 
upon conjecture or the personal observation of indi 
viduals, and, far too often, upon prejudice. There 
has not been in existence trustworthy statistical mate 
rial showing the effects of immigration. The United 
States Immigration Commission during the last four 
years has, however, gathered such material on a scale 
complete enough to enable a reasonably accurate judg 
ment to be formed regarding the effects of immigra 
tion. 
Both of the authors of this book were associated 
with the Commission from the beginning, and it has 
been their purpose to put into shape for the public, 
in such a manner that its significance may be readily 
understood by any thoughtful reader, the gist of the 
information collected in the forty-two volumes of the 
original material published by the Commission. Free 
use has been made of the data of the Commission and