Some of you might be interested in this book. To quote from a review by Christopher S. Grenda in the Journal of American History (volume 107 issue 1):
In The Pursuit of Happiness in the Founding Era, Carli N. Conklin seeks to disclose the original meaning of the phrase "the pursuit of happiness" in the Declaration of Independence. She maintains that the phrase was neither a synonym for private property or public spiritedness nor a foreshadowing of latter-day notions of personal fulfillment. Rather, Conklin argues that the authors and editors of the Declaration of Independence—Thomas Jefferson, John Adams, and Benjamin Franklin—as well as those who debated and approved the document in the Continental Congress understood the "pursuit of happiness" to mean the pursuit of virtue, the striving to live according to natural law.