While Louis D. Brandeis’s series of articles on the money trust was running in Harper’s Weekly many inquiries came about publication in more accessible permanent form. Even without such urgence through the mail, however, it would have been clear that these articles inevitably constituted a book, since they embodied an analysis and a narrative by that mind which, on the great industrial movements of our era, is the most expert in the United States. The inquiries meant that the attentive public recognized that here was a contribution to history. Here was the clearest and most profound treatment ever published on that part of our business development which, as President Wilson and other wise men have said, has come to constitute the greatest of our problems. The story of our time is the story of industry. No scholar of the future will be able to describe our era with authority unless he comprehends that expansion and concentration which followed the harnessing of steam and electricity, the great uses of the change, and the great excesses. No historian of the future, in my opinion, will find among our contemporary documents so masterful an analysis of why concentration went astray.