(Updated February 13, 2006) Project Mercury is now history. In its short span of four years, eight months, and one week as the Nation's first manned space flight program, Mercury earned a unique place in the annals of science and technology. The culmination of decades of investigation and application of aerodynamics, rocket propulsion, celestial mechanics, aerospace medicine, and electronics, Project Mercury took man beyond the atmosphere into space orbit. It confirmed the potential for man's mobility in his universe. It remains for Projects Gemini and Apollo to demonstrate that potential. Project Mercury was not only a step in the history of flight technology, it was a major step in national commitment to space research and exploration and to man's struggle to fly. One has only to contrast it with the Wright Brothers' achievements of sixty years ago, when two meticulous men, with a bicycle shop, a handmade wind tunnel, determination and industriousness, and little financial means or support, accomplished controlled, powered flight. The austere contrast of the Wrights or of Professor Goddard's rocket work with today's Government-sponsored, highly complex space program, involving thousands of persons and hundreds of Federal, industrial, and university activities, is eloquent testimony to the new prominence of science and technology in our daily lives. The evolution and achievements of Project Mercury offer an outstanding example of a truly national effort in the advancement of knowledge and its application. The Project Mercury story must be examined in the full context of its fundamental features - scientific, engineering, managerial - in the dynamic human environment of national and international life. Indeed, the national commitment to Project Mercury and its successors requires a valid perspective on the potential accomplishments of science and technology as well as on the response of a democratic society to the challenges of its day. This chronology of Project Mercury represents only a beginning on the full history, just as Mercury was only a first step in the development of American space transportation. No chronology is a history. This volume is but a preface to what is yet to come. Yet it offers us a catalog of processes by which man progresses from ideas originating in the human mind to the physical devices for man's travel to the moon and beyond.