The Thomas Edison Connection:
An associate and friend of Thomas Edison, Edward Johnson, is recognized as the first person to put electrified lights on a real Christmas tree. It happened in 1882 and just three years after the incandescent light bulb was invented. Johnson was a New Yorker and an executive of the Edison Illumination Company of New York City. Although the press smelled a publicity stunt, the event took place at Johnson's home in support of his belief in the lighting product's safety.
A "Safe" Christmas Tree Light:
Christmas trees before 1882 were displayed in homes with lighted candles - many tragic fires resulted from this custom. Edward Johnson hand-wired 80 red, white and blue hand-blown bulbs and strung them around a rotating evergreen tree. To quote Johnson from a letter sent to New York newspapers, "Electric trees will prove to be far less dangerous than the wax candle parlor trees." In fact, those first bulbs became very hot and were nearly as dangerous as the candles they were replacing.
Just Too Expensive:
Still out of range for most American families to purchase, Edison's christmas tree lights did not immediately catch on. It would take decades for affordable lighting to become available to most Americans. However, just after President Grover Cleveland commissioned a lighted White House tree in 1895, members of "high society" started hosting Christmas Tree parties. These events became more numerous even as the typical lighted tree of the early 1900s could cost as much as $300 ($2000 today).
Enter GE in 1903:
General Electric reduced the expense in 1903 by mass producing pre-assembled tree lighting for the very first time. The assembly was still too expensive for the average home but could be purchased or rented by department stores in electrified cities. The wiring consisted of eight green pre-wired porcelain sockets, eight colored glass bulbs and a plug for attachment to a nearby wall or ceiling light socket. GE was never able to obtain a patent on this string of lights called a "festoon".
Sadacca's Bird Cage:
In 1917, a 15-year-old boy named Albert Sadacca had a "light bulb" experience. Sadacca's family owned a novelty store selling electrified wicker bird cages with lighted imitation birds. Sadacca suggested to his parents that they begin making electric lights for Christmas trees. After a slow first year, the New York City novelty store grew into NOMA Electric Company and quickly became the largest Christmas lighting company in the world. NOMA lost their edge in 1965 to international competition.
Christmas Tree's "Tachon" Connector:
According to the National Electrical Contractors Association, "the bladed wall plug that we use today was actually a development of a device that was originally used to facilitate the interconnection of stings or festoons of Christmas lights. Some prototypes of this device were in use as early as 1917, and it was patented as the Tachon connector in 1924. The 1924 Tachon started out as a screw-in type of connector with a safety cover but soon evolved into the two parallel blade type."