Simplify the following text for a Grade 8 native English-speaking person.
Original: The Grito de Dolores ( `` Cry of Dolores '' ) also known as El Grito de la Independencia ( `` Cry of Independence '' ) , uttered from the small town of Dolores , near Guanajuato on September 16 , 1810 is the event that marks the beginning of the Mexican War of Independence and is the most important national holiday observed in Mexico .
Simplified: The Grito de Dolores ( `` Cry of Dolores '' ) marks the beginning of the Mexican War of Independence . It is also the most important national holiday in Mexico .