MODERN photographers have experienced some difficulty in securing proofs from the collodion negatives, due both to the years that the negatives have been neglected and their inexperience with the peculiar wet-plate process. Mr. Olsen is still working over them and has succeeded in stopping the chemical action that threatened to destroy many of them. Six thousand of the negatives are pronounced to be in as good condition today as on the day they were taken, nearly a half-century ago. Accompanying the collection is found an occasional negative that seems to have been made by Alexander Gardner or Samuel Cooley. Gardner was one of the photographers employed by Brady, but he later left him and entered into competition. Cooley was an early photographer who conceived a plan similar to Brady's, but operated on a very limited scale. Most of his negatives were taken in South Carolina. From this remarkable collection, witnessing the darkest days on the American continent and the first days of modern American photography, the prints are selected for these pages and are here dedicated to the American People. Until recent years there has been no mechanical process by which these negatives could be reproduced for general observation. The negatives are here accurately presented from the originals, by the modern half-tone process with only the slightest retouching where chemical action has made it absolutely necessary. In selecting these prints it has been the desire of the editor to present, as nearly as possible, a chronological pictorial record of the Civil War in the United States. At strategic points where the large cameras could not be drawn into the conflict, Brady used a smaller and lighter camera that allowed him to get very close to the field of action. Many of the most critical moments in the long siege are embodied in these small negatives. They link the larger pictures into one strong chain of indisputable evidence. It would require forty volumes to present the entire collection. This book can be but a kaleidoscopic vision of the great conflict. Thousands of remarkable scenes must for the present, at least remain unveiled. That the public may know just what these negatives conceal, a partial record has been compiled in the closing pages of this volume. It has been estimated that since the beginning of authentic history war has destroyed fifteen billions of human lives. I have seen the estimate put at twice that number. The estimated loss of life by war in the past century is fourteen millions. Napoleon's campaigns of twenty years cost Europe six millions of lives.