What significant event demonstrated AC's capacity and reliability on a grand scale, serving as a turning point?

Answer

The successful lighting of the 1893 World's Columbian Exposition in Chicago.

The successful operation of Westinghouse's AC system at the 1893 World's Columbian Exposition was cited as a massive public relations victory and turning point for alternating current.

What significant event demonstrated AC's capacity and reliability on a grand scale, serving as a turning point?
inventorCurrentelectricity