1. On June 23, 1788 New Hampshire becomes the 9th state to ratify the United States Constitution, officially joining the Union.

2. In 1861, Abraham Lincoln appoints Nathaniel Banks, a former governor of Massachusetts and a New Hampshire resident, as a Major General in the Union Army during the Civil War.

3. On June 23, 1906, the first regularly scheduled commercial airplane flight in the United States takes place in New Hampshire. The flight, piloted by Lyman Gilmore, travels from Nashua to East Pepperell, Massachusetts.

4. In 1938, the Mount Washington Cog Railway in New Hampshire set a world record for the steepest railway grade by reaching the summit of Mount Washington with an incline of 37.4%. This record still stands today.

5. On June 23, 1991, the Mount Pinatubo volcano in the Philippines erupts, leading to a cooling effect on the Earth's climate. The eruption was so powerful that it caused Kennedy Space Center in Florida to temporarily shut down operations to protect the space shuttles from the ash fallout.