For instance, we can look to the first ammendment:
Congress shall make no law respecting an establishment of religion, or prohibiting the free exercise thereof; or abridging the freedom of speech, or of the press; or the right of the people peaceably to assemble, and to petition the Government for a redress of grievances.
Nowhere do we see an endowment of a right. The rights that are discussed are believed natural rights. They existed without the government and the bill of rights sought to prevent the newly found government from infringing on such natural rights.
In fact, the 9th Ammendment states:
The enumeration in the Constitution, of certain rights, shall not be construed to deny or disparage others retained by the people.
This is precisely what you seek to do. You want to suggest that the rights "granted" are the rights possessed. Unfortunately this concept doesn't hold water. As we see in the 9th Ammendment rights are things that exist outside of constitutional grant. The constitution simply acknowledges them. And if the constitution does not specifically acknowledge them, they still exist.
So let us recap:
1) the constitution clearly acknowledges rights exist.
2) the constitution does not grant or endow some of these rights.
3) the constitution even acknowledges that there are rights that it did not specifically acknowledge (see 9th and 10th ammendments).
4) contemporary writings acknowledge and affirm natural rights.
5) you can show no evidence that the mutually exclusive belief that the founding fathers believed rights were created and granted by governments.