Grover Cleveland had one of the more straightforward tasks of his presidency on the evening of 1 May 1893. After saying a few words to the crowd, he pushed a gold button and hundreds of thousands of lightbulbs buzzed into life. It may not sound like much today, but no one had ever seen such a display of electrical power as the spectacle he switched on. The lights coruscated over the grand lake and illuminated the neoclassical buildings purpose-built for the occasion, while multi-coloured searchlights pierced the sky.


The Chicago World’s Fair had opened. Over the next six months, an estimated 27 million visitors flocked to this celebration of culture, invention, architecture, entertainment and a city reborn from the ashes of a devastating fire two decades earlier.

And as the bulbs kept shining and generators humming, the company providing the power claimed victory in a war of competing electrical systems. Genius inventors and industrialists – with Thomas Edison on one side, facing George Westinghouse and Nikola Tesla on the other – battled to lead the technological revolution that has powered humankind ever since. The success at the fair, essentially, declared the winner.

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Before the War of the Currents, Thomas Edison was already a household name. By the late 1870s, and barely in his 30s, the American developed an almost-magical sound-recording device called the phonograph, and set up his ‘invention factory’ at Menlo Park, New Jersey.

Then following months of testing, Edison demonstrated the world’s first practical incandescent lightbulb. It was a defining moment in his career, but perfecting a durable, safe and mass-produced form of electric light without the means to power it would be like inventing the car without fuel or roads. Edison needed an entirely new system and infrastructure for electrical distribution. The Edison Illuminating Company used direct current (DC), where energy flows constantly in a single direction in the same way as a battery. That powered his lightbulbs and he held the relevant patents, so Edison had a practical and strongly financial incentive to establish DC as the standard across the United States.

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Thomas Edison
Thomas Edison brought together inventors at Menlo Park, his invention factory. (Image by Bettmann/Getty Images)

Two systems

The first power station opened on Pearl Street, New York, in September 1882 and began serving 59 customers. As more plants followed, homes and businesses became connected and royalties soon flowed in, Edison parried press attacks from under-threat gas companies accusing electricity of being too dangerous. Yet these gains masked a much more serious problem – the unavoidable truth that DC had drawbacks.

It could not be transmitted over long distances without losing a lot of energy, so much so that plants had to be within a mile of customers. This involved more plants, more generators and more copper wiring. Plus, as DC ran at a constant rate, supplying different voltages would require separately installed lines, making it yet more expensive.

Alternating current (AC), where the flow reverses direction dozens of times per second, did not have these problems. A transformer, which went from a theoretical idea to functional use in the 1880s, could ‘step up’ the voltage, which allowed electricity to be transmitted far greater distances than DC with negligible loss. The high voltage would then be ‘stepped down’ by another transformer at the end of the line to make it safe for use. As the electricity could be transported long distances, plants could be larger – so there would be fewer of them – and cheaper to operate. AC used thinner copper too, bringing costs down further. It wasn’t perfected yet, though, as a fully functional system still missed some innovations and improvements. That was until a brilliant Serbian mathematician, engineer and visionary came along.

Columbian Exposition Hall
The streets of the 1893 World's Fair were lit up at night – as was the name of the man providing the power. (Image by Alamy)

Nikola Tesla, having travelled to America in 1884 with just four cents in his pocket, started out working at Edison Machine Works improving DC generators. He proved good at it, once staying up all night to repair the dynamos on the ocean liner SS Oregon. Like Edison, he worked long hours, slept little and had an unquenchable drive to innovate. But Tesla always believed the future of distributing electricity relied on AC, and left the job after Edison rejected his ideas as “splendid”, but “utterly impractical”.

An undeterred Tesla spent the next few years raising money for his own laboratory, including a stint digging ditches for Edison’s wires, and developing an AC system. His induction motor used a game-changing polyphase current (AC flowed in waves, so this filled in the ‘troughs’ with multiple voltages) to generate a rotating magnetic field (meaning fewer mechanical parts to maintain). Tesla had the ideas, but not the capital and business knowhow.

A Pittsburgh industrialist named George Westinghouse had both. Unlike his competitor Edison, who enjoyed his celebrity, Westinghouse kept himself private and did not like having his photograph taken. He was a savvy businessman, having made his fortune on the railroad, and immediately recognised the importance of Tesla’s work to his own ambitions for AC. As well as offering Tesla a job as a consultant, Westinghouse bought the patents for $60,000 in cash or stock and $2.50 for each horsepower of electricity sold – all worth millions today.

Edison v Westinghouse: your guide

The two men wanted the same thing – to control power distribution – but they had very different ways of achieving it

Before the war

Edison: Thomas Edison achieved worldwide fame in 1887 for his phonograph. He worked on the sound recording device, among other things, at the industrial research laboratory he set up – the first of its kind – at Menlo Park.

Westinghouse: After serving in the American Civil War, George Westinghouse made his fortune after inventing an air brake to greatly improve safety on the burgeoning railroads. The industrialist then established a company to ensure the adoption of his brake and signalling innovations.


Edison: Direct Current (DC) The electrical charge flows in a single direction at a constant voltage or current, as seen in a battery.

Westinghouse: Alternating Current (AC) The current changes direction multiple times a second. If plotted on a graph, AC looks like a wave of peaks and troughs.

Pros of the current

Edison: As Edison got there first, DC stations had become the standard (he even developed a meter so customers could be billed according to consumption). DC energy could be stored as back-up and flowed at lower, safer voltages.

Westinghouse: Crucially, AC could be transmitted over long distances without much loss. This meant that fewer power stations were needed than with DC, and they could cover more remote regions. It was easier and cheaper to generate too.

Cons of the current

Edison: DC had a small transmission range before losing significant amounts of energy. Power stations had to be within a mile of their customers – so were only cost-efficient in towns and cities – and required heavier, more expensive copper wiring.

Westinghouse: Transmitting AC over long distances meant stepping it up, using a transformer, to very high voltages. This meant that poorly insulated wires were extremely hazardous.

Wartime allies

Edison: Initially, Edison had the backing of hugely wealthy financiers JP Morgan and the Vanderbilt family, and all the resources of Menlo Park. In his attempts to demonstrate the dangers of AC, he colluded with electrical engineer Harold P Brown.

Westinghouse: Nikola Tesla, a Serbian mathematician and engineer, was a valuable partner with the genius to make AC work, while Westinghouse had the business acumen to sell it. Tesla sold him several patents concerning his polyphase motor for a large lump sum, shares and royalties.

Battle tactics

Edison: Edison launched a vicious smear campaign to discredit AC. This included electrocuting a menagerie of animals – from stray dogs to, in 1903, an elephant named Topsy – and the first human on the electric chair.

Westinghouse: His company sold at a loss in the early days to muscle into Edison’s monopoly and built stations in areas not covered by DC’s limited range. Westinghouse then secured the contract to light the 1893 World Fair in Chicago by underbidding the competition.

After the war

Edison: He continued inventing and developing the ideas of others (or buying them). Some were world-changing innovations – his motion picture projector, the Kinetoscope (pictured) – while a few proved less successful, notably his venture in mining iron ore.

Westinghouse: His company sold at a loss in the early days to muscle into Edison’s monopoly and built stations in areas not covered by DC’s limited range. Westinghouse then secured the contract to light the 1893 World Fair in Chicago by underbidding the competition.

In their own words

Edison: “Genius is one per cent inspiration and 99 per cent perspiration.”

Westinghouse: “If someday they say of me that in my work I have contributed something to the welfare and happiness of my fellow man, I shall be satisfied.”

Spreading shock

“George Westinghouse was, in my opinion, the only man on this globe who could take my alternating-current system under the circumstances then existing and win the battle against prejudice and money power,” said Tesla later in life. “He was one of the world’s true noblemen, of whom America may well be proud and to whom humanity owes an immense debt of gratitude.”

Westinghouse Electric Company, which had been created before Tesla’s involvement, posed a threat to Edison’s monopoly. Westinghouse targeted rural areas that could not be reached by DC’s small transmission range and managed to undercut rival business in the towns and cities by selling at a loss. By late 1887, he had built 68 power plants to Edison’s 121. To make matters worse, Edison faced competition from other DC companies too, such as Thomson-Houston. With the proliferation of electrical providers came expensive lawsuits over patents, which dragged on for years.

City street in a snowstorm
City streets were a spider's web of wires – but many broke during snowstorms. (Image by Bettmann/Getty Images)

Losing power, literally, and still struggling to make significant improvements to his own distribution, the ‘Wizard of Menlo Park’ refused to acknowledge the benefits of AC. It may have been down to pride or stubbornness, or because he had invested too much, or due to a sincere concern that his rivals’ high-voltage wires endangered people’s lives. Or all of the above. Whatever the reason, Edison showed how cutthroat he could be by launching a fearmongering smear campaign.

“Just as certain as death, Westinghouse will kill a customer within six months,” he had written in 1886. Sure enough, accidental electrocutions occurred when wires had been poorly installed or insulated as thousands of volts coursed through them, and Edison regularly used these deaths as fodder in his damning evidence against AC.

“Its effect upon muscular action is so great that even at exceedingly low voltage the hand which grasps a conductor cannot free itself… the nervous system of a human being could be shocked for a sufficient length of time to produce death,” he wrote in an 1889 article, The Dangers of Electric Lighting. Nevertheless, he continually claimed that his own DC remained perfectly safe. Westinghouse later recalled how Edison once said, “Direct current was like a river flowing peacefully to the sea, while alternating current was like a torrent rushing violently over a precipice”.

His campaign would go much further than rhetoric. Enlisting the help of electrical engineer Harold P Brown, he staged a number of grisly experiments where stray dogs (bought for 25 cents from local boys), calves and a horse would be brought to one of his laboratories and electrocuted. If animals did not make his point clearly enough, Edison also became embroiled in the adoption of the first electric chair to execute a human.

While he opposed capital punishment initially, an opportunity not to be missed fell into his lap. New York dentist Alfred P Southwick approached him concerning his desire for a more humane method of execution than hanging, believing electricity could be the answer. Edison had previously quipped that the best method would be to “hire out your criminals as linemen to the New York electric lighting companies,” but to Southwick, he recommended “alternating machines”.

Although an appalled Westinghouse refused to sell any of his generators for that purpose, Brown had been selected to design the chair based on Southwick’s ideas and he made sure it used AC. Edison even coined the term ‘Westinghoused’ to describe someone being electrocuted. So when convicted murderer William Kemmler was sentenced to die on the electric chair, Westinghouse spent $100,000 on his appeal – in vain as the Supreme Court rejected the argument that electrocution constituted a “cruel and unusual punishment”.

On 6 August 1890, guards strapped Kemmler into the AC-powered chair at Auburn Prison and flipped the switch. The 17-second burst of 1,000 volts did not kill him, so he had to be hit a second time, after an agonising wait while the generator charged. With double the voltage running through his body, Kemmler bled and his hair began to singe, while the smell of burning flesh made some witnesses retch. Westinghouse, on hearing about the bungled execution, stated, “They would have done better using an axe”.

The death of John Feeks

A spate of accidental electrocutions caused by the crisscrossing mess of overhead wires gave many reason to fear electricity, and fuelled Thomas Edison’s anti-AC crusade. The most gruesome death came on 11 October 1889. Western Union lineman John Feeks lost his footing while up a pole in downtown Manhattan and grabbed what should have been a low voltage telegraph wire – not knowing that it had become connected with a high voltage line several blocks away.

He died instantly, but his body got entangled in the web and it would take over half an hour for his fellow linemen to cut him free. All the while, Feeks burned. Blue spurts could be seen shooting out from the body and blood dripped down onto the street, where a lunchtime crowd of thousands had gathered, looking up in utter horror at the macabre scene. One newspaper described Feeks as “being slowly incinerated”. In the aftermath, wires in New York were cut down and moved underground, leaving the city without electricity over winter.

The war is won

Yet after all the bad publicity and attacks, Edison’s crusade failed to prevent the ascendency of AC or his profits from falling. His years of championing DC fizzled out as he stepped aside to pursue other projects and a merger in 1892 with Thomson-Houston turned his company into the more AC-friendly General Electric (GE).

The interior of General Electric's Building 12 at the Schenectady Plant. This is one of the original buildings in Edison Machine Works. (Photo by  Schenectady Museum; Hall of Electrical History Foundation/CORBIS/Corbis via Getty Images)
When Edison's company became General Electric, it completely refitted power plants to catch up with AC. (Photo by  Schenectady Museum; Hall of Electrical History Foundation/CORBIS/Corbis via Getty Images)

That did not stop the struggles for power with Westinghouse Electric, and it actually would not take long for GE to catch up once the commitment to DC had gone. The news that the Chicago World’s Fair of 1893 – also called the Columbian Exhibition to celebrate 400 years since Columbus reached the New World – would be powered by electricity set off a bidding war. It was another success for AC as Westinghouse won the contract by underbidding GE, providing his company with its most public and spectacular display yet.

Beyond the glittering sight of hundreds of thousands of lightbulbs outside, generators were on display in the Electricity Building and Tesla had a space to show off his work with his usual panache and showmanship. He demonstrated the theory of his induction motor by placing a copper egg into a rotating magnetic field, where it would spin on its axis of its own free will.

The fair, while a monumental triumph in its own right, also gave Westinghouse the reputation needed to secure the highly desired contract to build a hydroelectric plant on the Niagara Falls. By the time the great machinery began generating power, on 16 November 1896, for the city of Buffalo more than 20 miles away, there could be no doubt that AC had won the War of the Currents.

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This article first appeared in the March 2019 issue of BBC History Revealed magazine


Jonny Wilkes
Jonny WilkesFreelance writer

Jonny Wilkes is a former staff writer for BBC History Revealed, and he continues to write for both the magazine and HistoryExtra. He has BA in History from the University of York.