1. On December 1, 1870, the board of directors of Georgetown University made the decision to admit women to the university for the first time. This decision marked a major step forward for women's education in the district.

2. December 1, 1955, was the day that the Montgomery bus boycott began, a pivotal moment in the Civil Rights Movement. Although this event took place in Montgomery, Alabama, it had a significant impact on activists in the District of Columbia and inspired many protests and demonstrations throughout the city.

3. In 1961, President John F. Kennedy issued a proclamation designating December 1 as National Christmas Tree Day. This annual event features a lighting ceremony on the National Mall, and has become a beloved holiday tradition in the district.

4. December 1, 1973, marked the opening of the Smithsonian's National Air and Space Museum. This expansive museum, which is located on the National Mall, is dedicated to the history of flight and space exploration and is home to many iconic artifacts such as the Wright brothers' Flyer and Apollo 11's command module.

5. December 1, 1997, was the day that the United States Mint released the first state quarter in its fifty-six quarter series. The District of Columbia's own state quarter was released in 2009 and features an image of Duke Ellington, a famous jazz musician who was born in the city.