Final answer:
The origins of the Mexican flag can be traced back to the Aztec legend involving an eagle on a cactus, which became symbolic in the movement for independence led by figures such as Miguel Hidalgo and José Maria Morelos. The flag's symbolism was further cemented by acts of patriotism and valor, such as by cadet Juan Escutia during the U.S.-Mexico War.
Step-by-step explanation:
The Mexican flag has its roots in Aztec culture and history. According to the legend depicted in the Aztec Codex Mendoza, an eagle perched on a cactus with a serpent in its beak indicated to the Aztecs where to establish Tenochtitlán, their capital. This image would become central to the Mexican flag. The push for Mexican independence from Spain started in earnest with the priest Miguel Hidalgo y Costilla’s “Grito de Dolores” speech, which sparked the revolutionary movement. José Maria Morelos took over after Hidalgo’s execution and led to the formation of a constitution declaring Mexico's independence, which envisioned not just political but fundamental social changes.
Later, during the U.S.-Mexico War, the valor of Mexican defenders was symbolized by the legendary act of cadet Juan Escutia, who wrapped himself in the Mexican flag and leapt from the city walls rather than surrender it. The flag, hence, became a strong symbol of national identity and patriotic fervor. This flag, bearing the iconic eagle on a cactus symbol, represents the nation's rich history, the determination for independence, and the resilience and pride of its people.
Lastly, socio-political movements such as those by revolutionary philosopher Ricardo Flores Magón and the Plan de San Diego highlight the continued struggle for social justice and autonomy in the Mexican-American community, reflecting the enduring legacy and symbolism of the Mexican flag amongst the diaspora.