Nikola Tesla and George Westinghouse power the World's Columbian Exposition

The International Exposition was held in a building which was devoted to electrical exhibits.

General Electric Company (backed by Thomas Edison and J.P. Morgan) had proposed to power the electric exhibits with direct current originally at the cost of US$1.8 million. After this was initially rejected as exorbitant, General Electric re-bid their costs at $554,000. However, Westinghouse, armed with Nikola Tesla's alternating current system, proposed to illuminate the Columbian Exposition in Chicago for $399,000, and Westinghouse won the bid. It was a historical moment and the beginning of a revolution, as Nikola Tesla and George Westinghouse introduced the public to electrical power by illuminating the exposition. All the exhibits were from commercial enterprises. Thomas Edison, Brush, Western Electric, and Westinghouse had exhibits. The public observed firsthand the qualities and abilities of alternating current power.

World's Fair Tesla alternating current presentation
Tesla's high-frequency high-voltage lighting produced more efficient light with quantitatively less heat. A two-phase induction motor was driven by current from the main generators to power the system. Edison tried to prevent the use of his light bulbs in Tesla's works. General Electric banned the use of Edison's lamps in Westinghouse's plan in retaliation for losing the bid. Westinghouse's company quickly designed a double-stopper lightbulb (sidestepping Edison's patents) and was able to light the fair. The Westinghouse lightbulb was invented by Reginald Fessenden, later to be the first person to transmit voice by radio. Fessenden replaced Edison's delicate platinum lead-in wires with an iron-nickel alloy, thus greatly reducing the cost and increasing the life of the lamp.
The Westinghouse Company displayed several polyphase systems. The exhibits included a switchboard, polyphase generators, step-up transformers, transmission line, step-down transformers, commercial size induction motors and synchronous motors, and rotary direct current converters (including an operational railway motor). The working scaled system allowed the public a view of a system of polyphase power which could be transmitted over long distances, and be utilized, including the supply of direct current. Meters and other auxiliary devices were also present.
Tesla displayed his phosphorescent lighting, powered without wires by high-frequency fields, and employed a similar process, using high-voltage, high-frequency alternating current to shoot lightning from his fingertips.[citation needed] Tesla displayed the first practical phosphorescent lamps (a precursor to fluorescent lamps). Tesla's lighting inventions exposed to high-frequency currents would bring the gases to incandescence. Tesla also displayed the first neon lights. His innovations in this type of light emission were not regularly patented. Tesla also explained the principles of the rotating magnetic field and induction motor by demonstrating how to make an egg made of copper stand on end in his demonstration of the device he constructed known as the "Egg of Columbus".

Within the room was suspended two hard-rubber plates covered with tin foil. These were about fifteen feet apart, and served as terminals of the wires leading from the transformers. When the current was turned on, the lamps or tubes, which had no wires connected to them, but lay on a table between the suspended plates, or which might be held in the hand in almost any part of the room, were made luminous.”

— John Patrick Barrett