Thomas Jefferson is widely considered to be the primary author and most responsible for the Declaration of Independence. He was a key figure in the drafting committee appointed by the Second Continental Congress and was tasked with writing the document. Jefferson's eloquent writing style and his understanding of Enlightenment ideals influenced the powerful and persuasive language used in the Declaration. While the Declaration was a collective effort, Jefferson's contributions were crucial in shaping the document that declared the American colonies' independence from British rule and laid the groundwork for the formation of the United States of America.
I hope this helped!
~~~Harsha~~~