MEXICO CITY (AP) — The almighty eagle perched on a cactus while devouring a serpent on Mexico’s flag hints at the myth behind the foundation of the country’s capital. It’s a divine sign in an ancient legend, according to which the god Huitzilopochtli asked a group called the Mexica — who founded what was later known as the Aztec Empire — to leave their homeland in search of a place to establish a new city. It took some 175 years before they spotted the sacred omen and established the city of