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 (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, and in 1880, instead of $82,865,868,849, over three billions six hundred millions, or more than three 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 $150. As to the other Southern States, the excess is much greater. Now, if the annual products of the South were increased $150 each _per capita_ (still far below Massachusetts) by the exclusion of slavery, then multiplying the total population of the South, 12,229,727, by 150, the result would be an addition to the annual value of the products of the South of $1,834,456,050, and in the decade, $18,344,580,500. 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 in a decade, by the exclusion of slavery, to the value of the products of the South. 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 $287,000,000; and of Maryland, $66,000,000. Table 33 included domestic manufactories, 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 $235 _per capita_, and of Maryland, $96, 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. Some of these tables are given as follows: