1. The Washington Monument was officially dedicated on March 31, 1885. The monument is 555 feet tall and took over 40 years to complete. It is now one of the most recognizable landmarks in the nation's capital.

2. On March 31, 1968, President Lyndon B. Johnson announced that he would not seek re-election. This announcement came just a few weeks after the start of the Tet Offensive in Vietnam and marked the end of Johnson's presidency.

3. One of Washington's most famous residents, Duke Ellington, was born on March 31, 1899. Ellington was a renowned jazz composer and bandleader who wrote some of the most iconic songs of the 20th century, such as "Take the A Train" and "Mood Indigo."

4. The Vietnam Veterans Memorial was completed on March 31, 1982. The memorial, designed by Maya Lin, lists the names of over 58,000 Americans who died or went missing in action during the Vietnam War. It is one of the most visited memorials in Washington, D.C.

5. On March 31, 1801, the District of Columbia was officially placed under the jurisdiction of Congress. This was a significant moment in the history of the capital, as it marked the end of a long and contentious process of creating a seat of government for the United States.