IT has been wisely remarked by a distinguished American statesman, that the commencement of the Mexican War was the opening of a new volume of American history. Nations, like individuals, are often borne along in their progress, without pausing to consider the particular acts which are to shape and control their future destiny; and perhaps there is no subject on which the public mind is less likely to act with caution and deliberation than on the momentous question of peace or war.