1. On July 15, 1957, Delaware became the first state to allow women to serve on juries. The state's decision preceded the landmark U.S. Supreme Court decision in 1975 that upheld the right of women to serve on state juries.

2. On July 15, 1780, a British fleet of more than 40 ships arrived in Delaware Bay, sparking a battle known as the Battle of Cape May. The British sought to capture Philadelphia, but the American forces were able to repel the attack and prevent their advance.

3. On July 15, 1834, Delaware passed a law prohibiting the importation or sale of any slave from another state, effectively ending the practice of importing slaves to the state. This marked an important step in the state's transition to a free state.

4. On July 15, 1935, the DuPont Company introduced its new product, "Lucite," which revolutionized the world of plastics. The material was used for a wide range of applications, from car headlights to airplane windshields.

5. On July 15, 1972, Delaware's roadways were officially renumbered in a massive overhaul designed to make the system more efficient and easier to navigate. The state's old route numbering system had been in place since the 1920s, and the change was a major undertaking that required years of planning and execution.