I think the authors of that notable instrument intended to include all men, but they did not mean to declare all men equal in all respects. They did not mean to say all men were equal in color, size, intellect, moral development, or social capacity. They defined with tolerable distinctness in what they did consider all men created equal — equal in “certain inalienable rights, among which are life, liberty, and the pursuit of happiness.” This they said, and this they meant. They did not mean to assert the obvious untruth that all were then actually enjoying that equality, or yet that they were about to confer it immediately upon them. In fact, they had no power to confer such a boon. They meant simply to declare the right, so that the enforcement of it might follow as fast as circumstances should permit. They meant to set up a standard maxim for free society which should be familiar to all, constantly looked to, constantly labored for, and even, though never perfectly attained, constantly approximated, and thereby constantly spreading and deepening its influence, and augmenting the happiness and value of life to all people, of all colors, everywhere.

Abraham Lincoln (1809-1865) American lawyer, politician, US President (1861-65)
Lincoln-Douglas Debate, Alton, Illinois (15 Oct 1858)

On the Declaration of Independence.