1. In 1802, the District of Columbia officially became the nation's capital with the opening of the new United States Capitol building.

2. On January 18, 1865, Congress passed the 13th Amendment to the United States Constitution, which abolished slavery throughout the country.

3. In 1978, the Washington Metro's Red Line began operating from Farragut North to Rhode Island Avenue, becoming the system's first underground segment.

4. On January 18, 1983, Washington, D.C. Mayor Marion Barry announced a plan to create a new, state-of-the-art convention center in the heart of the city, which would open in 2003.

5. In 2009, Barack Obama was inaugurated as the 44th President of the United States in Washington, D.C, becoming the first African-American to hold the office. The inauguration ceremony was held on January 20th, but many inaugural events and celebrations occurred in the days leading up to it, including a concert on the National Mall on January 18th.