Thomas Jefferson: Autobiography, 6 Jan.-29 July 1821, 6 January 1821

nothing is more certainly written in the book of fate than that these people are to be free. nor is it less certain that the two races, equally free, cannot live in the same government. nature, habit, opinion has drawn indelible lines of distinction between them. it is still in our power to direct the process of emancipation and deportation peaceably and in such slow degree as that the evil will wear off insensibly, and their place be peri passu filled up by free white laborers. if on the contrary it is left to force itself on, human nature must shudder at the prospect held up. we should in vain look for an example in the Spanish deportation or deletion of the Moors. this precedent would fall far short of our case.