The isothermals of the great Humboldt (differing so widely from parallels), which trace the lines of temperature on the earth's surface, prove, as to heat, the climate of the South (running a line from Charleston to Vicksburg) to be substantially the same as that of Greece and Italyeach, in its turn, the mistress of the world. I know, when, the term isothermal was used in my inaugural as Governor of Kansas, it was represented by some of our present rebel leaders, to the masses of the South, as some terrible monster, perhaps the Yankee sea serpent; but I now use the term again in no offence, from its important application to the present case, and knowing that what I now advise would produce incalculable benefits to the whole country, but especially to the South. Indeed, if Texas, with her 274,356 square miles of area, with her salubrious climate, and fertile soil, already worked to a great extent by free labor, were a free State, she would, in time, contain a larger population than any State of the Union. Texas has much more than five times the area of England proper, and, with the same population to the square mile, would contain more than one hundred millions of people. Having, in 1837, offered in the Senate of the United States, and carried, the resolution, recognizing the independence of Texas, first proposing in my letter of the 8th January, 1844, the mode, by compact (alone practicable), by which, on my motion, Texas was admitted into the Union, distinctly advocating, in this letter, the reannexation of Texas, with, a view to secure the ultimate disappearance of slavery and negroism from the whole country, in opposition to the object officially avowed by Mr. Calhoun, to annex Texas for the purpose of perpetuating slavery, I shall, in a future letter, discuss this subject, involving not only our furnishing a certain abundant supply of cheap cotton, but securing the real monopoly of this great product, due to our peculiar soil and climate, and thus ultimately increasing our products and manufactures thousands of millions of dollars, and giving us the control of the commerce of the world.
If Maryland would only initiate this policy, and come now to the rescue of the Union from rebellion and foreign intervention, she would inscribe her name first of all the States on the page of history and in the gratitude of our country and mankind. The position of Maryland upon the Chesapeake, the Potomac, the Susquehanna, and Atlantic, is most commanding. She surrounds the Capitol. It was her own noble donation, and she is its natural guardian and sentinel. Her waters, cutting the Blue mountains and the Alleghany, flow into the Atlantic and Mississippi, thus making her an eastern and a western State. Throughout all her borders, not a citizen would lose anything by the change proposed, but all would be enriched. Take down the barriers of slavery, and a new and unprecedented current of population and capital would flow into the State. Property would rise immensely in value, the price of her lands would soon reach those of Pennsylvania, new towns and cities would spring into life, Cumberland would soon equal the great manufacturing sites of the North, and the railroad to Pittsburg would soon be completed. Baltimore would fulfil her mighty destiny, and the present canal up the Susquehanna, easily enlarged, so as to equal the grand work of New York, would connect her with Lakes Erie and Ontario. That canal already unites the Susquehanna from the Chesapeake with the lakes by the Seneca route (as it should by the Chenango also), and only requires to be enlarged to the extent of the Erie Canal, and the locks also, as wisely proposed in regard to that great work. This would at once develop the great iron and coal mines of the Susquehanna (anthracite and bituminous), supply western and central New York, and the great region of the lakes, and the Chesapeake with these articles, so essential in war and peace. Let the locks of the Erie Canal be enlarged as proposed, and the ship canal from the Illinois river to Chicago constructed; but in justice to Pennsylvania and Maryland, as vastly important for commerce and revenue, and as a war measure for the cheap construction of iron-clad gunboats in the great coal and iron region, and the defence of the lakes, the Chesapeake, the Delaware, the Albemarle, and of the capital of the Union, let this canal be enlarged also.
While this system of gradual emancipation would greatly promote the material interests of Maryland, and of all the border States, the President does not overstate its influence in crushing the rebellion and restoring peace.
Maryland, the border States, and the South would then indeed commence a new career of progress, by removing slavery and negroism; and their augmented wealth, and that of the whole country, would soon return to the Government, in increased revenue, a sum far exceeding the cost of gradual emancipation and colonization. Indeed, if, as a mere financial question, I was devising the most effective plan for liquidating the national debt and reducing our taxes, it would be thus vastly to augment our wealth and population by adopting this system.
The census of 1860 exhibits our increase of population from 1790 to 1860 at 35.59 per cent., and of our wealth 126.45. Now, if we would increase the wealth of the country only one tenth in the next ten years, by the gradual disappearance of slavery and negroism (far below the results of the census), then, our wealth being now $16,159,616,068, the effect of such increase would be to make our wealth in 1870, instead of $36,593,450,585, more than sixteen hundred millions greater, being more than three times our present debt, and in 1880, instead of $82,865,868,849, over three billions six hundred millions more, or more than seven times our present debt.
Before the close of this letter, it will be shown that the difference, per capita, of the annual products of Massachusetts and Maryland exceeds $120. As to the other Southern States, the excess is much greater. Now, if the annual products of the South were increased $120 each per capita (still far below Massachusetts) by the exclusion of slavery, then multiplying the total population of the South, 12,229,727, by 120, the result would be an addition to the annual value of the products of the South of $1,467,567,240, and in the decade, $14,675,672,400; the first amount being three times our debt on the 1st July, 1862, and the last sum thirty times our debt on that day. This change would not be immediate, but there can be no doubt that, with the vastly greater natural advantages of the South, the superiority of free to slave labor, the immense immigration, especially from Europe to the South, aided by the Homestead bill, and the conversion of large plantations into small farms, an addition of at least one billion of dollars would be made, by the exclusion of slavery, to the value of the products of the South, in the ten years from 1870 to 1880, which sum is more than double our public debt on the 1st July last.
Having considered the relative progress in population of Massachusetts and Maryland, I will now examine their advance in wealth.
By tables 33 and 36, census of 1860, the value of the products of Massachusetts that year was $283,000,000; and of Maryland, $65,583,000. Table 33 included domestic manufactures, mines, and fisheries (p. 59); and table 36, agricultural products. Dividing these several aggregates by the total population of each State, the value of that year's product of Massachusetts was $229.88 per capita, and of Maryland, $95.45, making the average annual value of the labor of each person in the former greatly more than double that of the latter, and the gross product more than quadruple. This is an amazing result, but it is far below the reality. The earnings of commerce and navigation are omitted in the census, which includes only the products of agriculture, manufactures, the mines, and fisheries. This was a most unfortunate omission, attributable to the secession leaders, who wished to confine the census to a mere enumeration of population, and thus obliterate all the other great decennial monuments which mark the nation's progress in the pathway of empire.