Old World & New World · Article 9 of 22 · 1545–1750
American silver helps join the Atlantic and Pacific economies
People & builders: Viceroy Francisco de Toledo (1515–1582); Andrés de Urdaneta (1498–1568); Ming and Qing merchants; Indigenous miners in Potosí
The mountains became a source of imperial revenue
Rich silver deposits were exploited at Potosí in the Andes from 1545 and near Zacatecas in northern New Spain from the 1540s. The Spanish crown expected wealth that could pay officials, soldiers and creditors. Silver production required costly mines, mercury refining, transport and labor. Colonial authorities used different forms of paid and coerced labor, including the Andean mita draft expanded under Viceroy Francisco de Toledo in the 1570s.
Mining towns drew supplies from distant farms, ranches and textile workshops. Indigenous communities supplied much of the labor and bore heavy social and environmental burdens. Potosí was a connected city, not an isolated hole in a mountain: the mine influenced roads, markets and administrative decisions across South America.
A Pacific connection changed the map of trade
After the establishment of a usable eastward return route across the Pacific associated with Andrés de Urdaneta in 1565, Spanish shipping connected Manila and Acapulco. Manila became a major Spanish colonial port in 1571. American silver purchased Asian silk, porcelain and other goods; merchants in China and elsewhere operated according to markets and policies of their own. The so-called Manila galleon trade was one part of wider networks, not evidence that Spain controlled the entire Pacific.
Large silver flows affected monetary systems and state finances, but their economic effects varied. Spanish monarchy was not made permanently solvent by mining wealth; repeated royal borrowing and warfare consumed revenues. Access to valuable commodities could finance expansion while creating dependency on coerced labor and unstable prices.
Why the consequences outlasted empire
Potosí’s landscape and the labor history of the Andes remain part of debates over extractive industry. Ports and ocean routes still connect raw materials, workers and wealthy buyers, although different firms and states now organize them. The pattern—resource extraction in one place, manufacturing and consumption elsewhere—would recur with cotton, coal, oil and electronics.
Colonial silver helped increase transcontinental exchange, but it also transferred environmental damage and control over labor onto communities that rarely determined the terms. The name of the mine can be found on maps; the names of most people who worked there cannot. That disparity is itself part of the historical record.
Dates & turning points
- 1545: Silver mining expands at Potosí.
- 1546: Major silver discoveries near Zacatecas support colonial mining.
- 1565: Spanish mariners establish a workable Manila–Acapulco return route.
- 1571: Manila becomes the center of Spanish colonial administration in the Philippines.