1. The Battle of Cooch's Bridge: On August 9, 1777, the Battle of Cooch's Bridge took place near Newark, Delaware. It was a small battle between American and British troops during the American Revolutionary War, but it was significant because it was the only battle fought on Delaware soil.

2. Delaware Becomes a State: August 9, 1787, is the day that Delaware became the first state to ratify the U.S. Constitution. It is often referred to as "The First State" because of this.

3. Charles Mason and Jeremiah Dixon: August 9, 1763, is the day that surveyors Charles Mason and Jeremiah Dixon began their work on the Mason-Dixon Line. The line was surveyed to establish the boundary between Pennsylvania and Maryland, but it later became known as the line separating the North from the South during the Civil War.

4. Second Battle of Fort Delaware: The Second Battle of Fort Delaware took place on August 9, 1864. It was a Confederate attempt to free prisoners held at the fort, but the Union forces were able to repel the attack.

5. Wilmington Race Riot: On August 9, 1968, a riot broke out in Wilmington, Delaware, following the assassination of civil rights leader Martin Luther King Jr. It was one of the most violent riots of the 1960s, resulting in the death of three people and the destruction of over 200 buildings.