1. On October 16, 1790, the Residence Act was signed by President George Washington, which designated the location of the country's new capital as the District of Columbia.

2. In 1859, a group of 21 slaves attempted to escape by taking control of a ship called The Pearl while it was docked in the Potomac River. The attempt was unsuccessful, but it brought attention to the issue of slavery in the nation's capital.

3. The Smithsonian American Art Museum, located in the District of Columbia, opened its doors on October 16, 1968, showcasing a collection of more than 7,000 works of American art.

4. On October 16, 1975, the Washington Metro, the city's subway system, began operation, with five stations serving the Red Line.

5. In 2002, the District of Columbia became the first jurisdiction in the United States to legalize medical marijuana, when a voter referendum passed with 69% approval.