Even though this line is said similarly in two of these important documents, the correct answer is The Declaration of Independence and here are some extra facts and evidence:
Thomas Jefferson was the principal author of the Declaration of Independence.
The actual sentence that these words are in is:
"We hold these Truths to be self-evident, that <u><em>all Men are created equal</em></u>, that they are endowed by their Creator with certain unalienable Rights..."
Please let me know if you have any further questions, Thank you!