Since the last quarter of the nineteenth century until the Great Depression, saltpeter (sodium nitrate) was the mainstay of the economy of Chile. The mineral compound, useful as fertilizer and as an explosive, is abundant in the far north, until the Pacific War (1879-1883) was under the sovereignty of Bolivia and Peru. Once this area became part of Chilean territory, there was a boom in the extractive industry, vitalized by European capitalists, particularly English.
Since the 1920s, both national elites and entrepreneurs nitrate noted with concern the decline of income from mineral, the fall in prices in foreign markets and the progress of competition, synthetic nitrate. The Guggenheim Brothers, American investment group with experience in the Chilean copper mining, decided to bet on the recovery of the industry based on a new processing method. The Chilean government put great hopes in the project and supported it with determination. This milestone represents the culmination of the gradual process of displacement of Europeans in the control of the industry, which will be left to U.S. interests.
The so-called Guggenheim method, created by engineer Anton Elias Cappelen Smith, derives its advantages from the fact based on a cold or warm water leaching of nitrate, at 30 degrees Celsius (in the system previously used Schanks broths were boiled at 105 degrees Celsius) . This allowed a substantial saving in fuel. Was more mechanized system, allowing operation with less manpower. Moreover, this method allowed to process with good yields relatively low grade ore, previously forced to dismiss the technology.
In 1925 the Guggenheim brothers began construction on the first floor which would work with the new technology, Saltpeter Office "Maria Elena", named after the wife of Cappelen. All the experience gained in this first settlement was overturned in the second and last of them, the Office "Pedro de Valdivia", built in 1931.
The Office "Pedro de Valdivia" is, like all schools nitrate fields, a true city, equipped with all facilities and services necessary for daily life of workers and managers, forced to live in an isolated and barren. It was built in 16 months, working on site almost 7000 people, who remained during that period in a temporary camp which still remain some precincts.
The Office is preserved until today without major changes in respect to what was in the 30s. The design divides three distinguishable areas: industrial plants properly so, the American neighborhood-for housing managers and supervisors, and working-class neighborhood. Of particular interest is the latter, with commercial and recreational facilities and joint linear-room houses. In the vicinity of the plaza, which has a beautiful tattoo kiosk, there were the most important buildings: the shop - "grocery store" - a theater with capacity for 800 people, the School and Social Club with lounge - dancing and swimming pool for workmen. Was farthest from the church, built in 1941, and the Hospital. In the area for mine facilities include the buildings of the winery and petty, the granulation tower, huge leach tanks and three fireplaces, plus the huge tailings cake almost fifty feet high.
The Office "Pedro de Valdivia, the most modern salt-producing center, could not give their original owners dividends they expected inaugurated amid the Great Depression, had to face before long the closure of foreign markets, and was stalled between 1932 and 1934. The nitrate industry never recovered, and the Guggenheim Brothers faced major losses under his bold projects. "Pedro de Valdivia" later passed into the ownership of the Chilean state and remained in operation until recently. The conservation and revaluation of its units is a goal of great importance, as this is a tribute to the thousands of men and women who labored painstakingly national prosperity in the nitrate pampa.