But there is another difficulty.  The great interior region bounded east by the Alleghanies, north by the British dominions, west by the Rocky Mountains, and south by the line along which the culture of corn and cotton meets, ... already has above ten millions of people, and will have fifty millions within fifty years, if not prevented by any political folly or mistake.  It contains more than one-third of the country owned by the United States,—­certainly more than one million of square miles.  Once half as populous as Massachusetts already is, and it would have more than seventy-five millions of people.  A glance at the map shows that, territorially speaking, it is the great body of the republic.  The other parts are but marginal borders to it, the magnificent region sloping west from the Rocky Mountains to the Pacific being the deepest, and also the richest, in undeveloped resources.  In the production of provisions, grains, grasses, and all which proceed from them, this great interior region is naturally one of the most important in the world.  Ascertain from the statistics the small proportion of the region which has, as yet, been brought into cultivation, and also the large and rapidly increasing amount of its products, and we shall be overwhelmed with the magnitude of the prospect presented.  And yet this region has no sea-coast, touches no ocean anywhere.  As part of one nation, its people now find, and may for ever find, their way to Europe by New York, to South America and Africa by New Orleans, and to Asia by San Francisco.  But separate our common country into two nations, as designed by the present rebellion, and every man of this great interior region is thereby cut off from one or more of these outlets,—­not perhaps by a physical barrier, but by embarrassing and onerous trade regulations.

And this is true, wherever a dividing or boundary line may be fixed.  Place it between the now free and slave country, or place it south of Kentucky, or north of Ohio, and still the truth remains that none south of it can trade to any port or place north of it, except upon terms dictated by a government foreign to them.  These outlets, east, west, and south, are indispensable to the well-being of the people inhabiting, and to inhabit, this vast interior region.  Which of the three may be the best, is no proper question.  All are better than either; and all of right belong to that people and their successors for ever.  True to themselves, they will not ask where a line of separation shall be, but will vow rather that there shall be no such line.  Nor are the marginal regions less interested in these communications to and through them to the great outside world.  They too, and each of them, must have access to this Egypt of the west, without paying toll at the crossing of any national boundary.

Our national strife springs not from our permanent part, not from the land we inhabit, not from our national homestead.  There is no possible severing of this but would multiply and not mitigate evils among us.  In all its adaptations and aptitudes, it demands union and abhors separation.  In fact, it would ere long force reunion, however much of blood and treasure the separation might have cost....