Thomas Jefferson drafted the principal text of the Declaration of Independence.
Congress appointed a five-person drafting committee consisting of Jefferson, John Adams, Benjamin Franklin, Roger Sherman, and Robert Livingston. The committee asked Jefferson to prepare the initial draft, which Congress then edited before adoption.
Jefferson was a delegate from Virginia and was 33 years old in 1776. The final document was not simply a private essay: it was revised and approved by Congress. This distinction explains why Jefferson is credited as the principal author while the Declaration remains an official act of the Continental Congress.