Salt is readily available almost everywhere on Earth – why do we still trade so much of it?

Salt wars, salt taxes and salt revolts – how and why we traded salt for millennia

Over thousands of years of humanity, civilizations invested enormous symbolism, prevented famine, waged wars, built and lost empires over a commodity that we now blithely toss by the millions of tons all over our icy streets in wintertime – salt.

Salt has such an important and varied role in health, religious life, death, wars and trade that a 450-page New York Times bestseller – called Salt, A World History by Mark Kurlansky – was written about it.

Sodium chloride (known commonly as salt) is versatile. Considered precious and therefore a source of great power throughout ancient history, in the modern era, refined salt is common and used extensively throughout the chemical industry. Gourmet varieties like fleur de sel season our food, but most of the salt mined is low-grade and deployed to de-ice our roadways. Given modern extraction techniques and geological understanding, we know salt is plentiful, so we no longer fight wars over it, but we do still trade it.

For sustenance and power

Ancient civilizations founded major cities and built empires near sources of salt, conquering and monopolizing saltworks as needed to maintain power. The ancient Mayans controlled salt resources at Salinas de los Nueve Cerros, an area in Guatemala where natural salt springs flowed into a river gully, enabling those who controlled it to trade salt and salted goods such as cured hides with downstream consumers.

Egyptians were among the earliest civilizations to preserve food on a large scale as insurance against crop failure in dry years. They evaporated seawater from the Nile Delta, but also likely procured salt through African trade with Libya and Ethiopia, as well as through Mediterranean trade. Trade spread knowledge about the use of salt for preservation (and taste) but also, according to Kurlansky, gave rise to trade in salted foods such as cured meats and fish, which “would shape economies for the next four millennia.”

From tuna, sardines, mackerel to sturgeon, salted fish was traded extensively as both food and medicine. Fishing industries flourished around port cities, especially based on trade in Atlantic cod, a fatless fish that was easily dried and salt-cured for transport. To support cod trade, the fearsome Vikings established “salt routes” that delivered delicate bay salt from Normandy back to the Baltic.

For wealth and control of trade

As the saying goes, “All roads lead to Rome.” One of the most famous was the Via Salaria or Salt Road that connected Rome to the saltworks at Ostia on the coast. Centuries later, the Italian city-states of Venice and Genoa staked their trading dominance on salt. Although Venice produced salt for themselves, the Venetian merchants realized they could make more money by controlling trade in salt.

Venice and Genoa contested control of as many saltworks throughout the Mediterranean as possible, jointly monopolizing the amount of salt available on the market and therefore the price at which salt was sold. Although the Genoese had a more sophisticated maritime industry and larger ships to hold bulk salt, the government in Venice ensured a landed price for importers by taxing its citizens. The subsidies to importers produced profits from salt trade with which to purchase Indian spices that they turned around and sold at lower prices than their competitors. The government plowed salt tax revenues back into loans to merchants, enabling Venice to dominate trade in spices, grain and textiles.

To wage war

Access to adequate salts stocks could affect the outcome of wars and is a recurring theme from early warfare through the U.S. Civil War. The livestock used to feed soldiers require salt, cavalry and workhorses hauling supplies and artillery require salt, and salt was needed to disinfect wounds. Napolean lost hundreds of thousands of troops in retreat from Russia due to starvation and lack of salt to treat wounds. The Union blocked Confederate ports in the south from receiving British salt and destroyed saltworks to weaken Confederate efforts. The Romans taxed their salt advantage to raise money to fight the Phoenicians and even paid soldiers in salt – the origins of the word “salary”.

To raise government revenue

Many governments have taxed this essential commodity, but their policies turned out to be not worth their salt. Protests against salt taxes were the proximate cause of many consequential revolts throughout history.

For centuries, French monarchs forced their subjects to buy salt from royal depots. Grievances against this practice helped spark a revolution against Louis XVI. The Moscow uprising of 1648 is known as the Moscow Salt Riot, instigated by the government’s replacement of different taxes with a universal salt tax to replenish the state treasury.

But perhaps the most well-known rebellion against oppression was the 1930 Salt March led by Mohandas Gandhi to protest British rule in India. For centuries, India had mined its ample natural salt fields, deposits and lakes. In particular, Orissa, located on India’s east coast, is home to a long and deep tract of natural salt beds, which even the poorest of residents could collect using simple techniques. Salt was traded for cotton, food and other necessities.

While it would have been convenient and cheap for the British government to avail itself of Orissa salt for gunpowder to fight its many wars with the French, doing so would have been detrimental to salt from Liverpool that could not compete on price or quality. The British took over salt production in Orissa, banning private production or sale, and subsequently imposed internal customs checkpoints to prevent smuggling. Duties were placed on salt from Orissa that were matched by duties on imports, generating government revenue and raising the price of salt for all Indians. Eventually, the government abandoned the Orissa saltworks causing a salt shortage and famine.

This breaking point became a foil for Ghandi’s “salt campaign,” a 240-mile march to the beach at Dandi where he scraped up a handful of salt in defiance of the British law that mandated the government monopoly. Soon thereafter, ordinary Indians resumed openly gathering and selling salt, fueling a movement that opened the door to future negotiations toward independence.

Today, India is a globally competitive producer with nearly 12,000 different salt manufacturers, mostly small scale, but still heavily regulated by the central government’s Salt Commissioner.

For security

Salt production was undertaken in China as early as 1,000 BC during the Xia dynasty and the Chinese can be credited with employing shaft wells, salt solution mining and percussion drilling techniques hundreds of years before anyone else.

China also has a longer legacy of state-control over production and trade of salt. Prices were kept artificially high. Salt revenues helped fund the Great Wall to defend against the Huns. Still today, the China National Salt Industry Corporation employs over 48,000 people charged with overseeing the national industry and China’s annual production of some 68.5 million tons.

For highways and factories

The many wars fought over production and trade of salt seem ironic and tragic in hindsight, considering that nearly every country in the world has salt deposits, not to mention that the salt content in the oceans is nearly unlimited.

Of course, today we enjoy the benefits of refrigeration, flash-freezing processes, and efficient transportation which all eliminate the need to preserve food by salt. Widespread use of modern drilling techniques and vacuum evaporators mean we can extract all the salt the world needs.

Why trade salt today?

The U.S. profile of salt consumption largely mirrors the way salt is used in most parts of the world. In 2018, 43 percent of salt consumed in United States went to de-ice our highways.

Another 39 percent was consumed by the chemical industry. Sodium chloride is a key raw material in the production of chlorine and caustic soda, which are used to manufacture glass, paper, rubber, PVC for construction, the dyes in textiles, as well as in water treatment and pharmaceuticals.

Just six percent went to agricultural and food processing. We can only eat so much of the stuff. Despite producing 42 million tons of salt worth $2.3 billion in 2018, we imported another 17 million tons, mostly from Chile, Canada and Mexico, mostly for our roadways and factories.

Who wins today’s salt wars?

These days, salt is traded peacefully – the wars are simply for market share. Leading salt exporters include The Netherlands, Germany, India, Chile and the United States. Given salt’s lead role in industrial manufacturing, it should be no surprise that the leading consumers of traded salt are Japan, China, Germany and the United States.

But while the chemical industry relies on sodium chloride to make so many things in our households, the majority of salt we pull from the Earth and trade around the world now lands unceremoniously beneath our feet and our car tires in winter.

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