Claim: Declaration of Independence of the Mexican Empire was ratified on September 28, 1821 at the National Archives (The Archivo General de la Nación).
Evidence: September 28, 1821 National Archives The Archivo General de la Nación (Spanish for "General Archive of the Nation"; abbreviated AGN) is charged by the Mexican state to "be the governing body of the national archives and the central consultative entity of the Federal Executive." 
On the afternoon of September 28, members of the Board met at the National Palace to draft the Declaration of Independence of the newly independent nation. It is home to some of the offices of both the Federal Treasury and the National Archives. The Archivo General de la Nación (Spanish for "General Archive of the Nation"; abbreviated AGN) is charged by the Mexican state to "be the governing body of the national archives and the central consultative entity of the Federal Executive." This founding document of the Mexican nation was drafted in the National Palace in Mexico City on September 28, 1821, by Juan José Espinosa de los Monteros, secretary of the Provisional Governmental Board.