1. In 1865, John Wilkes Booth, the assassin of President Abraham Lincoln, was surrounded by Union soldiers and killed in a barn in Virginia. Booth had fled to the District of Columbia after shooting Lincoln at Ford's Theatre on April 14.

2. In 1937, the Social Security Act was signed into law by President Franklin D. Roosevelt. The act provided retirement benefits for workers and their families, as well as unemployment insurance and aid to the disabled and dependent children.

3. In 1968, civil rights leader Stokely Carmichael was arrested outside the White House during a protest against the Vietnam War. Carmichael and other activists were demonstrating against the government's draft policies and the disproportionate number of African Americans drafted into the military.

4. In 1991, the first professional sports team in the District of Columbia in over 20 years, the Washington Bullets (now Wizards), advanced to the second round of the NBA playoffs. Led by stars such as Bernard King and Michael Adams, the Bullets defeated the Detroit Pistons in five games.

5. In 2010, Washington D.C. became the first city in the United States to legalize same-sex marriage through a legislative process. The D.C. City Council passed the Marriage Equality Act in December 2009, and it was signed into law by Mayor Adrian Fenty in March 2010. The first same-sex marriages in the District of Columbia took place on March 9, 2010.