[American Heritage Dictionary - Cite This Source - Share This en·dow (ěn-dou') Pronunciation Key
tr.v. en·dowed, en·dow·ing, en·dows

To provide with property, income, or a source of income.

To equip or supply with a talent or quality: Nature endowed you with a beautiful singing voice.
To imagine as having a usually favorable trait or quality: endowed the family pet with human intelligence.
Obsolete To provide with a dower.]

---- Endowed to me is a gift that has already been given/one that an individual already has or posesses. As in he/she is endowed (by nature) in the arts, science, etc. These 'gifts' should not be taken away, not by any individual or a governing state.

[American Heritage Dictionary - Cite This Source - Share This grant (grānt) Pronunciation Key
tr.v. grant·ed, grant·ing, grants

To consent to the fulfillment of: grant a request.
To accord as a favor, prerogative, or privilege: granted the franchise to all citizens.

To bestow; confer: grant aid.
To transfer (property) by a deed.
To concede; acknowledge: I grant the genius of your plan, but you still will not find backers.

n.
The act of granting.

Something granted.
A giving of funds for a specific purpose: federal grants for medical research.
A transfer of property by deed.
The property so transferred.
The deed by which the property is so transferred.
Law
A transfer of property by deed.
The property so transferred.
The deed by which the property is so transferred.
One of several tracts of land in New Hampshire, Maine, and Vermont originally granted to an individual or a group.]

----Granted is something that is 'allowed', as in by law to have. (mho)