No exhaustive study has, as yet, been made of the Napoleonic era with a view of determining the exact legal status of the blockades established by the British orders in council and the French decrees. It is the purpose of this work to point out the more salient features embodied in the principles of blockade during this period as set forth and laid down by the statesmen of the United States, Great Britain and France, together with their relations to the principles of international law. With this end in view, the treaties, conventions and diplomatic intercourse between the United States and these two foreign countries have been carefully studied. The opinions of statesmen and official legal counsel, as well as the diplomatic correspondence and the decisions of the admiralty courts must be accepted as, in a large measure, establishing the international principles upon which the legality of the various acts may be determined. Court decisions during this period, however, are too much influenced by expediency, made necessary by the demands of the times, to be unconditionally accepted as the last word on the legality of the points in question; but they will nevertheless be freely used.