1. Vermont Ratifies the U.S. Constitution (1788): On June 23, 1788, Vermont became the 14th state to ratify the U.S. Constitution. The state's ratification was significant because it was the first state to join the Union after the original 13 colonies.

2. Ethan Allen's Death (1781): Ethan Allen, a Revolutionary War hero and leader of the Green Mountain Boys, died on June 23, 1789. Allen was known for his role in capturing Fort Ticonderoga from the British in 1775.

3. Battle of Hubbardton (1777): The Battle of Hubbardton, a Revolutionary War battle fought between American and British forces, took place on June 23, 1777, in Hubbardton, Vermont. Although the Americans suffered a defeat, the battle prevented the British from easily moving southward.

4. Vermont's First Railroad Opens (1848): The Rutland & Burlington Railroad, Vermont's first railroad, opened on June 23, 1848. The railroad was a major development in Vermont's transportation infrastructure, allowing for faster and more efficient travel of people and goods.

5. Vermont Becomes a State (1791): On March 4, 1791, Vermont officially became the 14th state in the United States. However, it was on June 23 of that year that Vermont's state constitution was adopted by the state's General Assembly, solidifying its place in the Union.