1. On April 17, 1790, the first ever United States Census was conducted in Washington, D.C. The census recorded a total population of just over 3.9 million people, with Virginia having the largest population of any state.

2. In 1861, on April 17th, Virginia officially seceded from the Union, joining the Confederate States of America. This decision played a major role in the outbreak of the Civil War.

3. On April 17, 1907, over 2,000 women marched in Washington, D.C. as part of the Women's Suffrage Parade. The event was one of the largest suffrage demonstrations in American history, and helped to raise awareness of the women's suffrage movement.

4. In 1961, on April 17th, members of the Bay of Pigs invasion force were captured by Cuban forces. The invasion, which was supported by the United States, was an unsuccessful attempt to overthrow Fidel Castro's communist government.

5. On April 17, 1995, the Alfred P. Murrah Federal Building in Oklahoma City was bombed, killing 168 people and injuring hundreds more. The attack was carried out by domestic terrorists Timothy McVeigh and Terry Nichols, and remains one of the deadliest acts of domestic terrorism in American history.