Silver ore was discovered at Cerro Rico near present-day Potosí (Upper Peru, now Bolivia), triggering one of the largest silver booms of the early modern world and anchoring Spanish imperial revenues in Andean mining.
Juan de Tolosa’s expedition identified rich silver-bearing ore at Cerro de la Bufa near Zacatecas (New Spain, now Mexico), catalyzing a major northern Mexican mining district that would become central to Atlantic and Pacific silver flows.
Bartolomé de Medina developed large-scale mercury amalgamation (the patio process) at Pachuca, enabling profitable recovery from lower-grade ores and sharply expanding silver output in Mexico and later the Andes.
The Crown established the Real Audiencia of Charcas (seat at La Plata/Sucre), an administrative-judicial center that helped govern the region whose fiscal heart became Potosí’s silver complex.
Colonial cinnabar (mercury) mining began at Huancavelica (Peru), supplying crucial mercury for amalgamation-based refining and tying Andean mercury production directly to Potosí’s silver outputs.
The Manila–Acapulco galleon route opened a durable Pacific corridor. American silver—especially from Mexico—became a key payment medium for Asian goods, linking transatlantic and transpacific circuits.
Spain organized the treasure fleet convoy system to protect Atlantic shipping, channeling bullion (including Mexican and Andean silver) through escorted fleets that underpinned imperial finance and European payments.
A royal mint (Casa de la Moneda) was established at Potosí to coin silver near the source, strengthening fiscal control and producing coin that circulated widely in Atlantic and global trade.
Under Viceroy Francisco de Toledo’s reforms, the first colonial mita labor drafts reached Potosí, institutionalizing a rotating forced-labor system that sustained large-scale mining and refining.
The Potosí mint began striking silver coinage (including the 8 reales tradition), enabling standardization and high-volume monetization of Andean silver for shipment across the Spanish imperial system and beyond.
Potosí’s fiscal and productive boom crested in the 1590s; scholarship commonly marks 1592 as a peak year, after which output entered a long, uneven decline (with later 18th-century revivals).
A major debasement/fineness scandal at the Potosí mint spread mistrust through international markets that relied on Spanish silver coin, prompting investigations, executions of officials, and currency adjustments.
Spain transferred the Casa de Contratación—the institution overseeing Indies commerce—from Seville to Cádiz, reflecting shifts in navigation, administration, and the handling of transatlantic bullion and trade paperwork.
Spain created the Viceroyalty of the Río de la Plata, restructuring southern South American governance; this affected oversight and routing incentives for Upper Peruvian (including Potosí) silver and regional commerce.
Charles III promulgated the 1778 free trade regulation (within the empire), opening additional Spanish and American ports and loosening older monopoly patterns—reshaping legal routes by which silver and goods circulated.
The Real Ordenanza de Intendentes created the Intendencia de Potosí, part of Bourbon administrative reform intended to strengthen fiscal control and governance in key revenue-producing regions tied to silver.
Transatlantic Silver Trade: Potosí, Zacatecas, and Global Flows (1545–1800)
