The expedition of Messrs. Lewis and Clarke for exploring the river Missouri and the best communication from that to the Pacific Ocean has had all the success which could have been expected. They have traced the Missouri nearly to its source, descended the Columbia to the Pacific Ocean; ascertained with accuracy the geography of that interesting communication across our continent, learnt the character of the country, of its commerce and inhabitants; and it is but justice to say that Messrs. Lewis and Clarke and their brave companions have by this arduous service deserved well of their country. The attempt to explore the Red River, under the direction of Mr. Freeman, though conducted with a zeal and prudence meriting entire approbation, has not been equally successful. After proceeding up it about 600 miles, nearly as far as the French settlements had extended while the country was in their possession, our geographers were obliged to return without completing their work. Very useful additions have also been made to our knowledge of the Mississippi by Lieutenant Pike, who has ascended it to its source, and whose journal and map, giving the details of his journey, will shortly be ready for communication to both Houses of Congress. Those of Messrs. Lewis, Clarke, and Freeman will require further time to be digested and prepared. These important surveys, in addition to those before possessed, furnish materials for commencing an accurate map of the Mississippi and its western waters. Some principal rivers, however, remain still to be explored, toward which the authorization of Congress by moderate appropriations will be requisite. I congratulate you, fellow-citizens, on the approach of the period at which you may interpose your authority constitutionally to withdraw the citizens of the United States from all further participation in those violations of human rights which have been so long continued on the unoffending inhabitants of Africa, and which the morality, the reputation, and the best interests of our country have long been eager to proscribe. Although no law you may pass can take prohibitory effect till the first day of the year 1808, yet the intervening period is not too long to prevent by timely notice expeditions which can not be completed before that day. The receipts at the Treasury during the year ending on the 30th day of September last have amounted to near $15,000,000, which have enabled us, after meeting the current demands, to pay $2,700,000 of the American claims in part of the price of Louisiana; to pay of the funded debt upward of three millions of principal and nearly four of interest, and, in addition, to reimburse in the course of the present month near two millions of 5-1/2 per cent stock. These payments and reimbursements of the funded debt, with those which had been made in the four years and a half preceding, will at the close of the present year have extinguished upward of twenty-three millions of principal.