The literature describing the background of America's entry into the World War is being constantly expanded. Most of these additions are partisan or superficial; some, however, strive for objectivity and contribute to our understanding of that period. The present volume, the fruit of ten years of patient research, belongs decidedly to the latter category, even though on some points it will be called biassed. Dr. Tansill has examined, analyzed and synthesized the available sources, published and manuscript, both in the United States and abroad. On the whole his conclusions confirm the contention of the school of previous writers represented by Grattan and Millis that an important factor in the evolution of the United States from neutrality to war was an insufficiency of Congressional control over the President's conduct of foreign relations.