The Constitution of the United States may be characterized as a great invention, in the meaning of the word which is used in this book; and until 1850, it had worked with a success that surprised many of the statesmen and scholars of Europe. The problems placed before the nation had been many, various and difficult; but all had been solved with a sufficient degree of success for practical purposes; and the resulting situations had, on the whole, been met with courage, energy and intelligence. The Monroe Doctrine had been treated with respect, if not with entire acquiescence; the conduct of the Navy in the War of 1812 had demonstrated to Europe the fighting ability of our people; our scientific men, such as Franklin and Henry, ranked as high as any who had ever lived in any country; certain of our statesmen such as Franklin, held equal rank with statesmen anywhere; and the invention and first use of the electric telegraph had put America ahead of every other country in inventions of a basic kind. When we realize the rapid growth of the United States in the half century 1800-1850, and realize also that it was a growth almost _ab initio_, and note that the engineering materials of all kinds and all the knowledge of science in the country had come from Europe, we must admit that it is to the influence of invention, more than to any other one thing, that we owe the rapid progress of our country. As is the case with individuals, nations are prone to extol their own successes, and to take the entire credit for them. Americans are apt to thank themselves only for their amazing progress; but, in fairness, they should admit that without the inventions made in Europe and by Europeans, they would have had no means for even starting. The first locomotive used in the United States was brought from England. In Great Britain, the wars with France were under full headway in 1800, and her statesmen knew that she was faced with a danger so great that only the most strenuous exertions, and the utmost naval and military skill could overcome it. This danger was not overcome till the Battle of Waterloo in 1815. Thereafter, the progress of the nation was fairly quiet and assured, the main difficulties centering in the deplorable condition of the working classes, serious disturbances in Ireland and the mutiny in India.