1940: Glow in the Dark.

The Las Vegas Strip burns its way through 8,000 megawatts of electricity every day, much of it wired to the blinding agglomeration of LED signs beckoning visitors into the casinos. Neon signs have been around since 1910, but lighting those glass tubes requires a lot of voltage - something Las Vegas gained in 1936 with the opening of the Hoover Dam's dynamos. It's a pity, though, that younger visitors never got to see a not-so-distant past when the radiance of the Strip was solely the work of neon. [Extracted from the article]