1. On August 18, 1790, the capital of the United States was officially named the District of Columbia. This happened when Congress passed the Residence Act, which established a new federal district along the Potomac River.

2. In 1814, on August 18, British forces invaded and burned Washington, D.C. during the War of 1812. This event is famously known as the "Burning of Washington."

3. August 18, 1920, marked an important moment in United States' history, as it was the day that the Nineteenth Amendment was ratified, giving women the right to vote.

4. On August 18, 1966, protesters gathered outside the White House to demonstrate against the Vietnam War. This was part of a larger anti-war movement that took place across the United States during the 1960s and '70s.

5. August 18, 1991, was a significant day for the District of Columbia, as it was the date that the city officially gained home rule. This meant that the residents of D.C. had more control over local government affairs and the city's budget.