squisher
THE CALM ONE!!!!
Actually, LED's date back to the early part of the 20th century and were in wide use by the 70's.
Wide use? I had to do a quick google, what I read said they weren't even developed until the 60's, weren't really reliable until the 80's, weren't really easy to make multiple colors until the late 80's and weren't economical to make bright colors until the 90's.
I was only born in 1974 but it would seem to me only in recent times have they been in wide use.
http://www.marktechopto.com/Engineering-Services/history-of-leds-and-led-technology.cfm