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Woodblock print of Potosi hill. The image appeared in in Peru: a country study (1993) by the Federal Research Division, Library of Congress

A short story about Potosi—the largest South American silver mine—in the Library’s Collections (Part 2)

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This is a two-part blog post by Pamela Padilla, 2022 Summer participant in the Library of Congress Internship (LOCI) program with the Hispanic Reading Room, and a Library Science and History graduate student at Queens College, City University of New York

Click here for the first part of Pamela’s research project.

Woodblock print of Potosi hill. The image appeared in Peru: a country study (1993) by the Federal Research Division, Library of Congress.

At one point one of the most prolific mines in the world, Potosí reinforced Spain’s place in the global market. However, between the years 1550 and 1570, silver production had actually fallen, only to rise abruptly in 1572 and reach a peak in 1592. How did Potosí’s mines achieve this increase in production?

Historians attribute the rise in productivity to two major stimulants: the creation of the mita system and a new refining process, which combined mercury with silver to extract the silver from the ores. Potosí’s viceroy Francisco de Toledo (c.1515-1582) is largely responsible for these changes.

Map based on information from A. Curtis Wilgus, Historical Atlas of Latin America, New York, 1967, 112. The image appeared in Peru: a country study (1993) by the Federal Research Division, Library of Congress.

Toledo began tending to the mines within a year of his arrival in Peru in late 1569. Originally, the labor force of Potosí’s mines had been composed of a mixture of forced laborers and volunteers attracted to the work by the promise of profits. However, as extraction depleted the mines, a surge in incentivized labor seemed less and less likely. Thus, in 1572, Toledo began to devise a system for draft labor, which built on the Incan mita system. The mita, which means ‘turn’ in Quechua, was a form of taxation in which the government drafted participants, or mitayos, to work for a set amount of time on projects such as the construction of homes and bridges, or work in the mines. Though unpaid, the Incan mita system would ensure the well-being of the mitayo’s families.

Toledo’s modification of the mita divided the hundreds of villages in Potosí into 17 districts and required them to send about 1/7 (16%) of their able-bodied men each year to work. These men worked in the mines refining mills or at tasks assigned to them by overseers. Similarly, a smaller mita system existed in the mercury mines of the city of Huancavelica. Because the Potosí mita oversaw the management of tens of thousands of men in a language that was typically not Spanish, Toledo used caciques and kurakas, who had previously been Incan authorities, as middlemen to collect the workers and named five capitanes de la mita. In addition to his supervisory modifications, Toledo remunerated the work of the mita, however, it was still extremely poorly compensated. Word of this under-compensation reached the mitayos causing them to quit their jobs. However, before this happened, the middlemen would arrive with large quantities of food.

Pedro de Cieza de León, writer. Parte primera dela Chronica del Peru : que tracta la demarcacion de sus prouincias, la descripcion dellas, las fundaciones de las nueuas ciudades, los ritos y costumbres de los indios, y otras cosas estrañas dignas de ser sabidas. 1553. Jay I. Kislak Collection, Rare Book and Special Collections Division, Library of Congress.

Toledo also increased silver production at Potosí by refining ore through the use of mercury, a process historian Peter Bakewell has called amalgamation. Prior to its introduction, Potosí’s miners smelted rich ore in a guaira—a native Peruvian furnace that depended heavily on the wind. Amalgamation allowed for the utilization of less pure ore by milling the ore into a fine powder and exposing to mercury. While this process had achieved earlier success in Mexico’s mines, its use did not spread to Potosí until 1572, when Toledo encountered Pedro Hernandez de Velasco, a poor Spaniard from Mexico.

With the introduction of the amalgamation process came the establishment of refinery mills in the mid-1570s. As the number of refinery mills grew, so did Spain’s hold on the refining process to the detriment and exclusion of the Indigenous peoples by displacing their central role in the refining process.

Indigenous knowledge was crucial for the production in the mines. Without the help of the local communities, the Spanish bonanza and the economic boom that happened thereafter would not have been possible. Potosí’s mines and ancestral knowledge contributed to the expansion of the global market through its bullion, but its deep riches lie within its history and the reverberating impacts that touch our daily lives.

Keystone View Company, publisher.Overlooking an old Spanish silver mine, Cerro de Pasco, Peru. [between 1860 and 1910]. Stereographs Cards Collection, Prints and Photographs Division, Library of Congress.


Discover more

Cultural Exchanges in Quechua Dictionaries, A history of encounters told through lexicons. StoryMaps are multimedia storytelling publications on Library’s materials that can include rare books, photographs, audio recordings, music, maps, and more. All the Library’s StoryMaps can be found here.

Interconnecting Worlds: Weaving Community Narratives, Andean Histories & the Library’s Collections. This guide facilitates research about Andean peoples, cultures, and knowledges. It also connects Library of Congress collections to the Quechua language, storytelling & literature, visual arts, and music.

Library of Congress Research Guides Library’s guides organized by research topic and collections – these include both online materials, and materials only available on site. The guides related to the Caribbean, Iberian, and Latin American Studies can be found here.

Handbook of Latin American Studies (HLAS): A Resource Guide The Handbook of Latin American Studies is a bibliography on Latin America consisting of works selected and annotated by scholars. This link takes you to a selection of resources about Potosí in HLAS catalog. 

The PALABRA Archive at the Library of Congress The PALABRA Archive is a collection of original audio recordings of 20th and 21st century Luso-Hispanic poets and writers reading from their works. This link takes you to the audio recordings of South American authors. This other link takes you to PALABRA Indigenous Voices Project, a subset of the PALABRA Archive focused on poetry and literature written and spoken in Indigenous languages.

The Library’s catalog contains millions of records for books, serials, manuscripts, maps, music, recordings, images, and electronic resources. 

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