[upbeat music] Besides being the main ingredient in all of our favorite childhood things, like rubber duckies and bouncing balls, what can rubber tell us about the history of industrialization and resource development?

A lot, actually.

[upbeat music] While we might not think about rubber too much, unless we need to use the perfect comeback, "I'm rubber and you're glue," rubber is actually an incredibly important part of our daily lives.

It's in our car tires, sneakers, raincoats, building materials, garden hoses, cleaning gloves, and certain types of adhesives.

And historically, rubber was one of the most important materials used during the late 19th and early 20th centuries.

But rubber was not easy to come by.

And because of its relative scarcity in comparison with the demand for rubber at the turn of the century, control of the global rubber market was hotly contested, kind of like the price of a barrel of oil is today.

And just like oil, the demand for rubber drove intense competition between world powers hellbent on imperial expansion.

But before we get to all of that, we first have to ask ourselves: When did rubber become an essential natural resource, and why did it get so popular?

So, early Mesoamerican civilizations used rubber in a variety of ways, primarily to waterproof their clothing and to make different items, like rubber balls used in sports.

And this was 3,000 years before rubber's popularity in Western countries.

After the onset of colonization in 1492, rubber became a fascination in Europe and began getting incorporated into different products around the world.

So, natural rubber, harvested from rubber trees, was a novelty and a hot ticket.

But there was a very big problem with natural rubber-- it tended to melt in very hot weather and become hard and brittle in cold weather.

So, while there was excitement about waterproof cloth in the 1830s in Europe, this rubber fever began to taper off because of product failures.

So the fact that it was harvested from tropical regions, coupled with its instability during extreme shifts in the weather, didn't exactly make rubber an ideal candidate as a building material in Western countries.

But that all changed with a man named Charles Goodyear in 1839.

You know, the guy from the blimp.

While experimenting with rubber, he invented a process called vulcanization.

By heating rubber and combining it with sulfur and white lead, Goodyear discovered that he could reduce the stickiness of natural rubber and also prevent it from melting or cracking when the temperature changed.

He named this process after Vulcan, the Roman god of fire, and any resemblance to the Vulcan salute is purely coincidental.

So, Charles Goodyear's developments played a key role in changing rubber from a mere novelty to an industrial staple.

But just like any other resource where human demands surpassed the amount that can be produced naturally, rubber became a highly regulated and profitable business for Western nations with imperial ambitions.

And the history of rubber, labor, and imperialism follow similar trajectories of products such as sugar, cotton, and oil.

But that brings us to our next question: What was driving this new uptick in rubber demand?

Well, there's a good reason for the name "Goodyear" being synonymous with tires, because it was the late-19th century advent of the automobile that changed the shape of the rubber market.

Although the origins of the automobile could merit its own episode, the main takeaway is this: On January 29, 1886, two German inventors filed a patent for their gasoline-powered automobiles in two separate cities.

Their names were Karl Friedrich Benz and Gottlieb Daimler.

Yes, like Mercedes-Benz and Daimler Chrysler.

They had never met before, and Benz's model featured three wheels while Daimler's had four.

At the tail end of the 19th century and moving into the 20th century, the automobile industry exploded, driving up the demand for-- you guessed it-- rubber tires.

But this increase in demand led not only to the expansion of the auto industry but also to one of the most infamous cases of exploitation in world history.

In 1884 to 1885, King Leopold II of Belgium laid claim to a region of the African continent that he called "the Congo Free State."

King Leopold's main interest was enriching his own small nation through the harvesting of natural rubber in the Congo.

And because rubber demand was increasing, he saw this as an opportunity to gain huge profits for Belgium, which he did.

Leopold's rule wreaked havoc on the region.

He turned the area into a forced labor camp, and his soldiers were ordered to chop off the hands or otherwise mutilate and kill Congolese workers who did not comply or harvest enough rubber.

And estimated 8 to 10 million Congolese people died under King Leopold's rule from murder or overwork.

He was forced out of the region in 1908 due to international outrage over these atrocities.

But despite drawing the outward ire of the international community, Belgium maintained control of the Congo until 1960, so why isn't Leopold's story commonly told as one of the most notorious accounts of colonialism?

Well, that's because Belgium's control of the region was in line with the West's continued interests in dividing up the African continent amongst colonial powers.

But the history of rubber shifted again during World War II.

Demand for rubber was at an all-time high because it was needed for military supplies, like tires for tanks and airplanes and other vehicles.

Prior to the war, the U.S. had attempted to stockpile rubber from the British-controlled regions of Southeast Asia, but were only partially successful.

By May, 1940, they only had a three-month stockpile of natural rubber from British supplies.

From 1939 to 1945, the U.S. ran programs to find more uses for synthetic rubber.

By June of 1940, inventors had reinvigorated the call to make synthetic rubber, which had started in the 1860s.

Although earlier efforts had proven moderately successful, the new synthetic rubbers derived from petroleum and coal were more viable.

By 1940, Standard Oil and Firestone began releasing synthetic tires that could replace their natural-rubber counterparts.

And within two years, they were producing one million tons of synthetic rubber a year.

By the 1960s, synthetic rubber derived from petroleum began to account for 60% of the world rubber market, which it still does today.

This is probably why we hear more news stories about the price of a barrel of oil and little to nothing about the regulation of rubber, unlike our counterparts in the 19th and early 20th centuries.

So, how does this all add up?

Well, it seems like rubber has been around for thousands of years, but it wasn't until vulcanization and the invention of the automobile in the late 19th century that it actually became more important on the world stage.

This expansion of the rubber industry led to exploitation as demand grew, and it was the increased demand of the auto industry alongside scarcity during World War II that led to the increased production of synthetic rubber, which accounts for the majority of rubber products we use today.

But the history of rubber also shows us that the fight for natural resources isn't only regulated to things like coal and oil, but also items as seemingly innocent as our sneakers, raincoats, rubber bands, and snow tires.

So, even something as ordinary as household cleaning gloves can tell you something pretty important about world history.