The progress of events since the commencement of your last session has shown how soon difficulties disappear before a firm and determined resolution.  At that time such a road was deemed by wise and patriotic men to be a visionary project.  The great distance to be overcome and the intervening mountains and deserts in the way were obstacles which, in the opinion of many, could not be surmounted.  Now, after the lapse of but a single year, these obstacles, it has been discovered, are far less formidable than they were supposed to be, and mail stages with passengers now pass and repass regularly twice in each week, by a common wagon road, between San Francisco and St. Louis and Memphis in less than twenty-five days.  The service has been as regularly performed as it was in former years between New York and this city.

Whilst disclaiming all authority to appropriate money for the construction of this road, except that derived from the war-making power of the Constitution, there are important collateral considerations urging us to undertake the work as speedily as possible.

The first and most momentous of these is that such a road would be a powerful bond of union between the States east and west of the Rocky Mountains.  This is so self-evident as to require no illustration.

But again, in a commercial point of view, I consider this the great question of the day.  With the eastern front of our Republic stretching along the Atlantic and its western front along the Pacific, if all the parts should be united by a safe, easy, and rapid intercommunication we must necessarily command a very large proportion of the trade both of Europe and Asia.  Our recent treaties with China and Japan will open these rich and populous Empires to our commerce; and the history of the world proves that the nation which has gained possession of the trade with eastern Asia has always become wealthy and powerful.  The peculiar geographical position of California and our Pacific possessions invites American capital and enterprise into this fruitful field.  To reap the rich harvest, however, it is an indispensable prerequisite that we shall first have a railroad to convey and circulate its products throughout every portion of the Union.  Besides, such a railroad through our temperate latitude, which would not be impeded by the frosts and snows of winter nor by the tropical heats of summer, would attract to itself much of the travel and the trade of all nations passing between Europe and Asia.

On the 21st of August last Lieutenant J.N.  Maffit, of the United States brig Dolphin, captured the slaver Echo (formerly the Putnam, of New Orleans) near Kay Verde, on the coast of Cuba, with more than 300 African negroes on board.  The prize, under the command of Lieutenant Bradford, of the United States Navy, arrived at Charleston on the 27th August, when the negroes, 306 in number, were delivered into the custody of the United States