1. On February 15, 1812, the state of Delaware officially adopted its state flag. The flag features a diamond shape in the center with the state coat-of-arms on a background of colonial blue. The flag serves as a symbol of the state's unique heritage and history.

2. In 1870, on February 15th, the first successful billiard tournament was held in Wilmington, Delaware. The tournament brought together some of the best players from around the region, and it helped to establish billiards as a popular competitive sport throughout Delaware and the surrounding areas.

3. On February 15, 1923, the Wilmington Blue Rocks baseball team was officially established. The team, which is still in operation today, has a rich history of success in the minor leagues, and it has produced many notable players who have gone on to play in the major leagues.

4. On this day in 1933, Delaware became the first state to ratify the 21st Amendment, which repealed Prohibition and legalized the sale and consumption of alcohol. The amendment was later ratified by the required number of states and became law later that year.

5. In 1970, on February 15th, Delaware's Governor Russell Peterson signed the Coastal Zone Act into law. The act was designed to protect Delaware's 115-mile coastline from industrial development and pollution, and it remains one of the most progressive environmental protection laws in the country. The act paved the way for the creation of the Delaware Coastal Management Program, which is still in operation today.