Treaty of Córdoba
The Treaty is the first document in which Spanish ( without authorization ) and Mexican officials accept the liberty of what will become the First Mexican Empire , but it is not today recognized as the foundational moment , since these ideas are often attributed to the Grito de Dolores ( September 16 , 1810 ) . 
<triplet> Grito de Dolores <subj> September 16, 1810 <obj> point in time