Don't ask don't tell was repealed. President Obama signed the repeal of the don't ask, don't tell policy that governed the recruitment and service of LGBTQ members in the United States military. The policy was put in place by the Clinton Administration in 1994.

Romanian President Nicolae Ceaușescu overthrown. The Communist President was ousted after widespread demonstrations in the country. Ceaușescu and his wife Elena tried to flee the country, but were captured, tried and executed by a firing squad. The Romanian Revolution was the only violent overthrow of a communist government in the 1980s.

Lincoln Tunnel opens. The 1.5-mile-long (2.4 km) long tunnel passes under the Hudson River and connects New Jersey to New York City.

First asteroid discovered through astrophotography. 323 Brucia was discovered by Max Wolf and was named after Catherine Wolfe Bruce, an American patron of astronomy.

First Christmas tree to be illuminated by electric lights displayed. Edward H. Johnson, an associate of inventor Thomas Edison and the Vice President of the Edison Electric Light Company, became the first person to decorate a Christmas tree with electric lights at his home in New York City.