The late 1800s was an exciting time for electricity and power transmission. On one side, Thomas Edison had successfully commercialized his version of the incandescent lightbulb and was pushing for direct current (DC) to be adopted as the standard for electrical power distribution in the United States. On the other side was Nikola Tesla, an inventor and engineer who firmly believed that alternating current (AC) was far superior to DC for transmitting electricity efficiently over long distances. What ensued was one of the most famous battles in industrial history, now known as the War of the Currents.

Edison's DC Power System

Thomas Edison was one of the most famous inventors and businessmen of his time. In 1879, Edison created the first practical incandescent lightbulb and went on to form the Edison Electric Light Company in 1880, delivering DC electricity to customers in a small area of Lower Manhattan.

Edison was convinced that DC was the ideal form of electricity for lighting and power. At the time, DC systems had already been installed in cities across America. The major advantage of DC was that the voltage could be changed using a transformer, allowing it to be used for lighting, motors and appliances in businesses and homes.

However, Edison's DC systems had a severe limitation - the generating station could only supply electricity within a radius of approximately one mile. This was because at the time, there was no way to efficiently change DC voltage for transmission over long distances. To get power farther out, Edison began building power stations in every neighborhood, connected via cables in underground tubes.

Tesla's Breakthrough with AC Power

At the same time, Nikola Tesla was gaining attention for his remarkable work with AC electricity. An immigrant from Serbia, Tesla arrived in America in 1884 and quickly found work with Edison. However, Tesla left Edison's company after only six months due to a financial dispute.

Tesla secured funding from investors and founded the Tesla Electric Light and Manufacturing Company in 1886. He filed numerous patents on AC motors and transmission systems. Most importantly, Tesla had solved the problem of changing AC voltage using a device called an induction coil, or "transformer." This meant that AC power could be easily transmitted over much greater distances than Edison's DC.

Advantages of AC Power Transmission

Nikola Tesla's AC system had several major advantages over Edison's DC power:

Clearly, AC was a vastly more economical technology for power transmission. But Edison didn't give up his beloved DC without a fight.

Edison's Propaganda Campaign Against AC

Despite the advantages, Edison continued to claim that DC was the safest form of electricity. He launched propaganda campaigns against high voltage AC power, attempting to frighten the public by emphasizing its risks.

In particular, Edison highlighted that AC could be fatal if improperly installed or handled. To prove his point, Edison conducted macabre public demonstrations where animals were electrocuted using AC. He held one such demonstration in1903, electrocuting a rogue circus elephant named Topsy using a Westinghouse AC generator in front of 1500 spectators.

Edison also publicly stated that AC systems were inefficient compared to DC and that consumers would end up paying higher costs for AC power. However, these claims were misleading or outright false.

Victory for Tesla's AC Current

The deciding factor came down to economics. In 1893, entrepreneur George Westinghouse won a contract to light the 1893 World's Columbian Exposition in Chicago using Tesla's AC system. Westinghouse underbid rivals with an AC system that was far cheaper than Edison's DC network.

The exposition was a huge success, impressively illuminating over 200 buildings along more than a mile of waterfront. It demonstrated theclear advantages of AC power on a grand scale.

After the exposition, AC began to be more broadly adopted across America. Within a few years, AC networks had become the norm for transmitting power across cities and regions. By the late 1890s, Edison's DC systems were essentially obsolete, save for some low voltage applications.

Nikola Tesla's revolutionary advancements with AC current had won the War of the Currents. His technology drove the electrification of the United States and laid the foundations for modern electric power. Although Edison tried to cling to his DC technology, AC proved to be vastly superior for efficient, economical transmission and distribution of electricity.


The War of the Currents marked a titanic shift for electrical distribution. Despite Edison's attacks against AC, Tesla's superior technology prevailed based on performance, practicality and cost-effectiveness. This victory for Tesla's polyphase AC system enabled widespread adoption of affordable electricity and powering of the Second Industrial Revolution. The AC grid he pioneered now powers the modern world.