EXPLANATION. THE red line on the United States Map here presented, designates an uninterrupted course of inlandnavigation through the several sections of the country. The line includes within it, the connecting artificial works described in the table hereafter inserted; and it has its terminations at the Atlantic sea-ports, at those of the Gulf of Florida, and at Columbia river-mouth on the Pacific. Engraved lines on the map, shew the several routes of Main post road in the United States, from Washington city towards the different extremities of the country, as described in the table which follows. A profile or vertical section of the Hudson and Lake Erie canal, is shewn on this map. Ir is to illustrate what has been said of the country's surface, and the facilities for internal conveyance, which, from nature and artificial works conjointly, are likely to exist, that I have caused to be prepared this sheet-map of the United States, extended Westward to the Pacific. A military survey of our whole line of sea-coast and frontier by land, is prosecuting by an able corps of engineers, under the orders of government; and at the next session of congress, it is probable there will be made a detailed and very luminous report upon the subject, comprising all matters in relation to fortifications already constructed or in execution, and all projects of defensive works against future emergencies. I state this fact, particularly as it is susceptible of having a strong bearing upon the water-improvements now pending; that is to say, in the event of the General government deciding to engage in the construction of any canal or canals, for military defensive purposes. The constitution of the United States is clear, at least on this point, and leaves us in no doubt as to authority for all needful undertakings of this description. A national high road between Washington city and New Orleans, has. been projected, and the subject been much canvassed, and it is thought that government will cause the road to be made. It will be seen, on inspection, that engraved lines on the maps are made to radiate from the city of Washington, and branch out towards the different extremities of the country; so as to represent the several Main routes of post-road; which may be enumerated, and, together with the cross post-roads, be summed up, as to distance, thus: TABLE OF POST-ROADS. The great North Eastern line of road, viz. From Washington city varied via From Washington city varied via From Boston, Mass. to Concord, N. H., 868 Miles. 154 131 84 The South line of road, viz. From Washington city to St. The North Line. From Washington city to fort Niagara, via Har risburg and Buffalo, The North Western line, viz. From Fredericktown, Md. to De troit in Michigan Territory, Miles. 161 373 1,771 808 88 896 470 The West line of road, viz. From Washington city to St. Lou- From Pittsburg to Chillicothe, From Athens to Portsmouth, 957 208 174 75 1,414 |