Thomas Jefferson never explained his use of the phrase "pursuit of happiness" in the Declaration of Independence. He was almost certainly influenced by George Mason's Virginia Declaration of Rights (adopted June 12, 1776), which referred to "the enjoyment of life and liberty, with the means of acquiring and possessing property, and pursuing and obtaining happiness and safety."1

Jefferson's rough draft of the Declaration of Independence used the expression, "... life, & liberty, & the pursuit of happiness."2 In the final version, Jefferson altered the wording slightly to read "... Life, Liberty and the pursuit of Happiness."3

Further Sources

• Ellis, Joseph J. "The Spring of '76: Texts and Contexts." In What Did the Declaration Declare?, edited by Joseph J. Ellis, 79-94. Boston: Bedford/St. Martin's, 1999. See especially pp. 88-90.
• Gerber, Scott Douglas, ed. The Declaration of Independence: Origins and Impact. Washington, D.C.: CQ Press, 2002.
• Maier, Pauline. American Scripture: Making the Declaration of Independence. New York: Knopf, 1997.
• Schlesinger, Arthur M. "The Lost Meaning of the 'Pursuit of Happiness'." William and Mary Quarterly 3d ser. vol. 21, no. 3 (1964): 326-27.  Focuses mostly on the use of the word "pursuit."
• Look for further sources in the Thomas Jefferson Portal.

• 1. The full text of the Virginia Declaration of Rights, along with draft versions and other related documents, is available online at "George Mason & Historic Human Rights Documents," provided by "George Mason's Gunston Hall."
• 2. Jefferson’s "original Rough draught" of the Declaration of Independence, June 11-July 4, 1776, in PTJ, 1:423. Transcription available at Founders Online.
• 3. The Declaration of Independence as Adopted by Congress, June 11-July 4, 1776, in PTJ, 1:429. Transcription available at Founders Online.