To the Members and Committees of the Congress, the Constitution is more than a revered abstraction; it is an everyday companion and counsellor. Into it, the Founding Fathers breathed the spirit of life; through every subsequent generation, that spirit has remained vital. In more than a century and a half of cataclysmic events, the Constitution has successfully withstood test after test. No crisis--foreign or domestic--has impaired its vitality. The system of checks and balances which it sets up has enabled the growing nation to adapt itself to every need and at the same time to checkrein every bid for arbitrary power. And meantime America itself has evolved dynamically and dramatically. The humble 13 colonies, carved out of the wilderness in the 18th Century, emerged in the 20th Century as leader of earth--industrial--military--political--economic--psychological. Yet the broad outline of the Supreme Law remains today fundamentally intact. It is small wonder that W.E. Gladstone described the Constitution as "the most wonderful work ever struck off at a given time by the brain and purpose of man." He knew, as should we, that the Constitution's words, its phrases, clauses, sentences, paragraphs, and sections still possess a miraculous quality--a mingled flexibility and strength which permits its adaptation to the needs of the hour without sacrifice of its essential character as the basic framework of freedom. Congress has long recognized how necessary it is to have a handy working guide to this superb charter. It has sought a map, so to speak, of the great historical landmarks of Constitutional jurisprudence--landmarks which mark the oft-times epic battles of clashing legal interpretations. A first step was taken toward meeting this need by publication of Senate Document 12, 63d Congress in 1913. Ten years later, in 1923 another volume was issued, Senate Document 96, 67th Congress, and it was followed in turn by Senate Document 154 of the 68th Congress. In 1936, Congress authorized a further revision, this time by the Legislative Reference Service. Mr. Wilfred C. Gilbert, now the Assistant Director of the Service, was the editor of this volume which became Senate Document 232, 74th Congress, and he has given counsel throughout the development of the present edition of this volume. After another decade of significant and far-reaching judicial interpretation, the Senate Judiciary Committee reported out Senate Joint Resolution 69 of the 80th Congress calling upon the Librarian of Congress for the preparation of the new work. However, because of the increase in responsibilities of the Legislative Reference Service, it was no longer feasible for it to undertake this additional burden with its regular staff. The Director of the Service, Dr. Ernest S. Griffith, suggested therefore that Dr. Edward S. Corwin be engaged to head the project with a collaborating staff to be furnished by the Legislative Reference Service.