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Martin Luther possibly sparked the tradition -

The person who kick-started the tradition of holiday lights is believed to be Martin Luther, the 16th-century Protestant reformer and priest.

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Martin Luther possibly sparked the tradition -

It's said that he became so enchanted by the stars shining through an evergreen forest that he brought a tree into his home and tied candles onto its branches.

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Thomas Edison invented the first electric Christmas lights -

Determined to electrify downtown Manhattan, Thomas Edison sought to draw attention to his incandescent light bulb during the 1880 Christmas season.

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Thomas Edison invented the first electric Christmas lights -

Edison laid 8 mi (12 km) of underground wire to power strings of lights around the outside of his New Jersey lab. Train commuters traveling between New York and Philadelphia were so amazed by the glowing fields that one reporter labeled Edison "The Enchanter."

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Edison's colleague Edward H. Johnson created the first electrically illuminated Christmas tree -

However, it was only in 1882 that these lights were used for decorating purposes. During that holiday season, Edison's colleague Edward H. Johnson strung 80 colored electric lights around a Christmas tree in Edison's lab.

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Edison's colleague Edward H. Johnson created the first electrically illuminated Christmas tree -

The lights were a huge success, and they quickly became a popular way to decorate for the holiday season.

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Grover Cleveland was the first president to have a Christmas tree decked out in electric bulbs -

Benjamin Harrison was the first to have a Christmas tree in the White House in 1889, but it wasn't until 1895 that Grover Cleveland (pictured) requested the First Family's tree be decorated with hundreds of multicolored bulbs. This was four years after the White House received electricity.

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Grover Cleveland was the first president to have a Christmas tree decked out in electric bulbs -

Cleveland is credited with warming the American public to the idea of electric Christmas lights. At the time, many people mistrusted electricity and thought that dangerous vapors would enter their homes through the lights and wires.

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The first Christmas lights were expensive -

By 1900, it could cost as much as US$300 (around $10,000 today) to pay for the lights, a generator, and a wire man's services to illuminate a Christmas tree with electric lights.

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The first Christmas lights were expensive -

On top of that, early electric Christmas lights were hand-wired and made with delicate glass bulbs, which contributed to the high price tag.

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A 15-year-old helped popularize electric Christmas tree lights for private use -

In 1917, a tragic fire in New York City (caused by candles on a Christmas tree) inspired then-teenager Albert Sadacca to adapt the novelty lighting his parents sold for Christmas trees. While only a hundred strings sold in the first year, once Sadacca painted the bulbs red, green, and other colors, the business took off.

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A 15-year-old helped popularize electric Christmas tree lights for private use -

In 1926, Sadacca started the National Outfit Manufacturers Association, a trade group of several small companies that consolidated into the NOMA Electric Company. NOMA became the largest Christmas light company in the world until the mid-'60s.

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Early lights were elaborate -

Many of the early light bulbs were blown from the molds that were also used to make glass ornaments. They were then painted by toy makers.

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Early lights were elaborate -

The paint would often flake due to the heat generated by the light, so milk glass was typically used to make the flaking paint less noticeable.

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Christmas lights weren't safe for outdoor use until the '20s -

President Calvin Coolidge (pictured) was responsible for the first National Christmas Tree in 1923. Adorned with 2,500 red, white, and green electric bulbs, for most of the country outdoor lights wouldn't be widely available until 1927.

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Christmas lights weren’t safe for outdoor use until the '20s -

To increase sales, General Electric and various distribution companies sponsored neighborhood "decorating with color-light" contests, a tradition that continues to this day in the US.

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Hargrove Inc. decorate the National Christmas Tree -

For more than 60 years, Hargrove Inc. has decorated the National Christmas Tree in Washington, D.C. In 1954, when this tradition began, Earl Hargrove had to install each light individually.

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Hargrove Inc. decorate the National Christmas Tree -

When a bulb stopped working, Hargrove dressed up as Santa and proceeded to climb up the tree to replace the malfunctioning light.

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The Christmas light cemetery -

When Christmas lights break or no longer work, they're often sent to Shijiao, China. Each year, the city receives around 20 million pounds (nine million kg) of lights.

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The Christmas light cemetery -

There, the lights get broken down for their copper and wire insulation, and recycled into new products.

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The Guinness World Record for the "most lights on a residential property" belongs to a family in New York -

In 2014, the Gay family reclaimed the Guinness World Record for the most lights on a residential property. They strung a total of 601,736 lights around their home in LaGrangeville, New York.

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The Guinness World Record for the "most lights on a residential property" belongs to a family in New York -

The family nearly doubled their display since breaking the record in 2012 with 346,283 lights.

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Blinking Christmas lights rely on a simple thermostat -

Those twinkling lights work through a simple design. When electricity heats a strip of metal in the bulb, it bends and breaks the circuit.

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Blinking Christmas lights rely on a simple thermostat -

As the metal cools, it bends back and reconnects the circuit to create an intermittent flashing effect.

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Hanging outdoor lights (and other decorations) can be dangerous -

According to the Consumer Product Safety Commission (CPSC), thousands of people are treated in emergency rooms around the US for injuries connected to holiday lights, Christmas trees, ornaments, and other decorations during the holiday season.

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Hanging outdoor lights (and other decorations) can be dangerous -

The most common injuries are falls, lacerations, and back strains. So be careful when you're getting those Christmas lights up!

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Fires from Christmas lights still pose a risk -

While electric lights have reduced the risk of fire tremendously, the CPSC estimates that fire departments respond to several hundred fires each year in which the Christmas tree was the first ignited item. 

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Fires from Christmas lights still pose a risk -

To prevent fires, make sure to water real trees frequently, unplug lights when leaving home, and discard damaged holiday lights.

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Christmas lights can help reduce crime -

On another note, a study by the University of Pennsylvania found that neighborhoods with more Christmas lights had lower crime rates.

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Christmas lights can help reduce crime -

The researchers believe that the lights make the neighborhood feel more welcoming and cohesive, which can deter burglars.

Sources: (Mental Floss) (The Week) 

See also: The best sweet treats to make at home for the holidays

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