Who was the principal author if the declaration of independence?

Thomas Jefferson is often credited as the sole writer of the document, but the Declaration (1776) was a collaborative effort.

Jefferson was the one responsible for writing both the first and final draft. However, he was actually part of a committee appointed by the Second Continental Congress to write it. The other four members were Benjamin Franklin, John Adams, Robert R. Livingston and Roger Sherman, all of whom provided recommendations on the language of the document.

Thomas Jefferson was the main writer of the Declaration of Independence. The Draft of which was heavily edited by the Continental Congress can be seen in: Adrienne Koch and William Peden eds., The Life and Selected Writings of Thomas Jefferson (New York: Random House, 1944).
Thomas Jefferson