The Constitution of 1812, known as La Pepa, was promulgated by the Cortes of Cádiz during a tumultuous period marked by warfare and foreign occupation. As Spain battled against Napoleonic forces, the need for a unified national identity and governance was urgent. Convened in the city of Cádiz, which remained free from French capture, the Cortes assembled representatives from across Spain, including its colonies. They drafted a constitution that reflected irreversible societal changes sparked by Enlightenment ideas and revolutionary movements worldwide.

The Constitution established a parliamentary system and placed sovereignty in the hands of the people rather than the monarch. It outlined fundamental rights, including freedom of the press, equality before the law, and the separation of powers. The constitutional framework aimed to modernize Spain and curb the absolute authority of King Ferdinand VII, emphasizing civic rights that appealed to both liberals and progressive factions in Spanish society. Furthermore, the constitution incorporated provisions for the autonomy of Spain's colonies, indicating an early recognition of their distinct identities.

Despite the constitution's progressive ideals, its implementation faced enormous challenges. After the war, King Ferdinand VII annulled it, reinstating absolute monarchy and limiting many of the liberties granted. However, La Pepa became a symbol of the struggle for democracy and human rights in Spain and Latin America, influencing liberal movements in the years to come. It set a precedent for future constitutional developments within the nation and inspired the push for constitutional governance beyond Spanish borders, making it a significant milestone in both Spanish and Latin American histories.