1. In 1787, Delaware became the first state to ratify the United States Constitution. The state is known as the "First State" as a result of this historical event.

2. The Wilmington & Western Railroad was incorporated on May 25, 1867. The railroad was instrumental in the transportation of goods and people throughout the state and helped to shape the growth of towns and cities in the area.

3. On May 25, 1937, the DuPont Company opened its nylon plant in Seaford, Delaware. The facility was the first to produce nylon commercially and helped to revolutionize the textile industry.

4. The Delaware Memorial Bridge, which spans the Delaware River and connects Delaware and New Jersey, opened on May 25, 1951. The bridge is an important transportation link for the Northeastern United States and is one of the longest twin suspension bridges in the world.

5. Delaware's first female senator, Mary L. W. Pickersgill, was appointed to the U.S. Senate on May 25, 1935, by Governor C. Douglass Buck. She served until 1936 and was the first woman to be appointed to the Senate.