1. On September 17, 1862, the Battle of Antietam took place near Sharpsburg, Maryland, which was one of the bloodiest battles of the American Civil War. More than 23,000 soldiers were killed, wounded, or missing after 12 hours of fighting.

2. In 1908, the Washington Senators played their last game at American League Park, which was located near what is now National Airport. The Senators moved to a new stadium, Griffith Stadium, in the same year.

3. On September 17, 1961, President John F. Kennedy dedicated the Greyhound Lines bus terminal in Washington, D.C. The terminal, which was designed by architect W. A. Storrer, was hailed as the finest bus station in the country at the time.

4. The National Museum of Natural History opened its doors to the public on September 17, 1910. The museum, which is part of the Smithsonian Institution, has since become one of the most popular tourist attractions in the city.

5. On September 17, 2011, the Martin Luther King Jr. Memorial was officially dedicated on the National Mall. The memorial features a 30-foot-tall statue of the civil rights icon, as well as several quotations from his speeches and writings.