Publication of this second edition has allowed me to make a few minor factual corrections and to eliminate the errors in spelling, punctuation, and syntax that invariably find their way into printed works irrespective of the most diligent efforts to avoid them. I am particularly grateful to those book reviewers who have called them to my attention. Most of them were kind enough not to mention such errors in their reviews.
But the book, as written in 1952, stands. I have had no good reason till now to re-examine or to revise my original findings.
For the history of American socialism after 1901, T refer the reader to David A. Shannon The Socialist Party of America ( New York, 1955). Professor Shannon and I planned our volumes to dovetail and his study consequently takes up where this one leaves off.
University of Massachusetts
August 1, 1963