Surprise! Surprise!  christmas_lights

Thomas Edison, the inventor of the first successful practical light bulb, created the very first strand of electric lights. During the Christmas season of 1880, these strands were strung around the outside of his Menlo Park Laboratory. Railroad passengers traveling by the laboratory got their first look at an electrical light display. But it would take almost forty years for electric Christmas lights to become the tradition that we all know and love.

From the Library of Congress website