The work originally published under the title of THE NEW AMERICAN CYCLOPÆDIA was completed in 1863, since which time the wide circulation which it has attained in all parts of the United States, and the signal developments which have taken place in every branch of science, literature, and art, have induced the editors and publishers to submit it to an exact and thorough revision, and to issue a new edition entitled THE AMERICAN CYCLOPÆDIA. Within the last ten years the progress of discovery in every department of knowledge has made a new work of reference an imperative want. The movement of political affairs has kept pace with the discoveries of science, and their fruitful application to the industrial and useful arts and the convenience and refinement of social life. Great wars and consequent revolutions have occurred, involving national changes of peculiar moment. The civil war of our own country, which was at its height when the last volume of the old work appeared, has happily been ended, and a new course of commercial and industrial activity has been commenced. Large accessions to our geographical knowledge have been made by the indefatigable explorers of Africa. The great political revolutions of the last decade, with the natural result of the lapse of time, have brought into public view a multitude of new men, whose names are in every one's mouth, and of whose lives every one is curious to know the particulars. Great battles have been fought, and important sieges maintained, of which the details are as yet preserved only in the newspapers, or in the transient publications of the day, but which ought now to take their place in permanent and authentic history. In preparing the present edition for the press, it has accordingly been the aim of the editors to bring down the information to the latest possible dates, and to furnish an accurate account of the most recent discoveries in science, of every fresh production in literature, and the newest inventions in the practical arts, as well as to give a succinct and original record of the progress of political and historical events. The work has been begun after long and careful preliminary labor, and with the most ample resources for carrying it on to a successful termination. None of the original stereotype plates have been used, but every page has been printed on new type, forming in fact a new Cyclopædia, with the same plan and compass as its predecessor, but with a far greater pecuniary expenditure, and with such improvements in its composition as have been suggested by longer experience and enlarged knowledge.