Thomas Jefferson (1743-1826) is a late-eighteenth-century and early-nineteenth-century American writer who is the principal author of The Declaration of Independence (1776) and who composes many works about political philosophy and statesmanship. In the twentieth and twenty-first centuries, most critics regard Jefferson as one of the great philosopher-statesmen because his writings often advocate the ideas of democracy, human rights, liberty, and political independence. Completely different from this perspective, this essay focuses its emphasis on Jefferson’s effectiveness as a natural history writer. The aim of this essay is to point out that through his natural historical discourse in Notes on the State of Virginia (1787) and letters, Jefferson describes and studies the flora, fauna, geography of America, helping ground American national culture upon the land, thereby constructing a distinctive national culture for early America. In this way, this essay hopes to refer the readers interested in an alternative view to the writings of Jefferson.