1. On June 23, 1683, William Penn signed a treaty with the Lenni-Lenape Native American tribe, now known as the Delaware Indians, establishing peaceful relations and land ownership rights between the settlers and the indigenous people in Pennsylvania.

2. June 23, 1757 saw the beginning of the Battle of Fort Beauséjour during the French and Indian War. The battle took place near the present-day border between Nova Scotia and New Brunswick, but it ultimately had significant consequences for Pennsylvania, as the war influenced the boundaries and territorial claims of the state.

3. Pennsylvania experienced a historic heat wave on June 23, 1931, with many cities across the state setting new record high temperatures. The town of Phoenixville recorded a scorching 106 degrees Fahrenheit, which remains the highest temperature ever recorded in Pennsylvania.

4. On June 23, 1940, William H. Hastie was appointed as the first African American federal judge in the United States. Hastie, a Pennsylvania native, had previously served as the first black governor of the U.S. Virgin Islands.

5. June 23, 1972 marked the passage of the Pennsylvania Solid Waste Management Act, which established a framework for managing the state's growing waste problem. The law created new regulations for landfills and sparked the development of recycling programs across Pennsylvania, making it a leader in waste reduction and environmental stewardship.