“We hold these truths to be self-evident, that all men are created equal, that they are endowed by their Creator with certain unalienable Rights, that among these are Life, Liberty and the pursuit of Happiness.”
Did the Founders make these rights fully effective, or even try to? Nope. But I believe they were here expressing an ideal for which we should continue to strive till it has been achieved.
As so often, Lincoln expressed my thoughts best, in his final debate with Douglas:
“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, nor 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 mean 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.”
His phrasing resonated then, and still does today. He had the ability to make the listener feel good.
In the passage you quote, it wasn't until the first sentence that I disagreed with what he was saying: “I think the authors of that notable instrument intended to include all men. . .”
I'm not comfortable saying this but “no they did not.” Slaves were not considered citizens by the founders and the founders did not include any provision to engraft them.
Lincoln did a good job papering-over the conflicts he had with the founding fathers. He was - well - Linconesque.