This is a line written by Thomas Jefferson that appears in the US Constitution. Francis Miville has some very interesting comments on Jefferson’s original intentions in deciding to use that phrase.
For your information, when Jefferson spoke about the pursuit of happiness, he didn’t mean happiness as most of us probably do. Instead he tried to translate the Latin fortuna, meaning “fortuitous,” which is that which happens to you according to fate, especially regarding financial fortunes. You were supposed to be the sole person responsible for your fortuna, otherwise you renounced an essential qualification of a free man.
The proof of this analysis is that he hesitated a lot between choosing between the phrases “pursuit of happiness” and “pursuit of felicity.” In other words Jefferson was speaking in Economic Darwinian terms far more vulgarly closer to a “bagger” than you can imagine. This is especially if you discover that he was considered by others and himself as Voltaire’s late successor and continuator in the New World.
In Jefferson’s eyes, the only way to be someone was to inherit a mansion together with at least 100 personnel in your service. This is what he meant by “we the people” in which the spirit of the nation resided. All so-called “Enlightenment” philosophers had no great individuality themselves and strove not to have any part in the quantitative degree of their success.
The word “happiness” in the more emotional romantic sense arose as a concept after the defeat of Napoleon and the triumph of Byron meaning “bliss” or if you found that too simple, “felicity.”
What “Enlightenment” philosophy called “reason,” which was supposed to make the only difference between man and beast was financial cunning, which Voltaire made very clear through throughout thousands of pages of his writing. Jefferson was but the continuation of the Voltaire’s prose.
For these two authors, “humanity” meant the community of those who were akin to the “humanities” in the literary classical sense of the word. These were people who were authorized to have access to the “humanities” by their guardians and the opinion this group controlled.
All great Enlightenment philosophers made it very clear that personal interest for them was not enough to be part of “humanities.” Instead, if you were a mere laborer, having personal interest was considered social felony.