We find, by the census of 1810, that the number of slaves in the Union was then 1,191,000. In 1820, they had increased to 1,538,000. That is to say, in ten years, they had increased 29 per cent.--within three per cent of that rate of increase which would double their numbers in twenty-five years. We may, we think, fairly calculate that, if the female slaves had been as numerous as the males, and if no manumissions had taken place, the census of the slave population would have exhibited an increase of 32 per cent, in ten years. If we are right in fixing on 32 per cent, as the rate at which the white population of America increases by procreation in ten years, it will follow that, during the last ten years of the eighteenth century, nearly one-sixth of the increase was the effect of emigration; from {247}1800 to 1810, about one-ninth; and from 1810 to 1820, about one-seventeenth. This is what we should have expected; for it is clear that, unless the number of emigrants be constantly increasing, it must, as compared with the resident population, be relatively decreasing. The number of persons added to the population of the United States by emigration, between 1810 and 1820, would be nearly 120,000. From the data furnished by Mr. Sadler himself, we should be inclined to think that this would be a fair estimate. “_Dr. Seybert says, that the passengers to ten of the principal ports of the United States, in the year 1817, amounted to 22,235; of whom 11,977 were from Great Britain and Ireland; 4,164 from Germany and Holland: 1,245 from France; 58 from Italy; 2,901 from the British possessions in North America; 1,569 from the West Indies; and from all other countries, 321. These, however, we may conclude, with the editor of Styles’s Register, were far short of the number that arrived_.”