1. Maryland became the seventh state to ratify the U.S. Constitution on September 15, 1788. This important milestone helped to solidify the young nation and establish Maryland as a key player in the new government.

2. On September 15, 1830, the Baltimore and Ohio Railroad began operations, becoming the first commercial railroad in the United States. This breakthrough in transportation technology allowed goods and people to travel faster and more efficiently throughout the region.

3. In 1957, Maryland Governor Theodore McKeldin officially opened the Baltimore Civic Center on September 15. The venue hosted many important events over the years, including concerts, athletic competitions, and political conventions.

4. On September 15, 1977, the historic Waverly mansion in Howard County was destroyed by fire. The mansion had stood for over 150 years, and its loss was a major blow to Maryland's architectural heritage.

5. In recent years, September 15 has been designated as National Hispanic Heritage Month in the United States. This celebration recognizes the contributions and achievements of Latino Americans throughout the country, including in Maryland, where Hispanic communities have been growing rapidly in recent decades.