1. On September 19, 1862, the Battle of Antietam took place in Sharpsburg, Maryland. It was the bloodiest single-day battle in American history, with 23,000 casualties.

2. On September 19, 1796, the Maryland Jockey Club was founded in Baltimore. The club is still in operation today and is responsible for organizing some of the most important horse races in the country.

3. In 1901, the first automobile in Montgomery County was driven on September 19. The car was a 12-horsepower Oldsmobile and it was driven by Dr. John R. King in Bethesda.

4. On September 19, 2003, the Howard County Conservancy was founded in Woodstock, Maryland. The organization is dedicated to preserving and promoting the natural and cultural heritage of Howard County.

5. In 1885, the Baltimore Orioles played their last game of the season on September 19. This was the first year that the team was part of the American Association, and they finished the season with a record of 63 wins and 43 losses.