There are Alternative Hypotheses to the source of Jefferson’s use of Pursuit of Happiness:
If, in reality, courage and a heart devoted to the good of mankind are the constituents of human felicity, the kindness which is done infers a happiness in the person from whom it proceeds, not in him on whom it is bestowed; and the greatest good which men possessed of fortitude and generosity can procure to their fellow creatures is a participation of this happy character. If this be the good of the individual, it is likewise that of mankind; and virtue no longer imposes a task by which we are obliged to bestow upon others that good from which we ourselves refrain; but supposes, in the highest degree, as possessed by ourselves, that state of felicity which we are required to promote in the world.
—Adam Ferguson, An Essay on the History of Civil Society
Ferguson, Adam (1995) . Oz-Salzberger, Fania, ed. An Essay on the History of Civil Society. Cambridge, NY: Cambridge University Press. pp. 99–100.
Wills, Gary (2002) . Inventing America: Jefferson’s Declaration of Independence. New York, NY: Mariner Books.