1. In 1822, the Pennsylvania State Legislature approved the incorporation of the Pennsylvania Academy of the Fine Arts (PAFA), the first art museum and school in the United States.

2. In 1885, the first commercial electric power station in the United States began operation in Philadelphia. The station, built by inventor Thomas Edison, provided electricity to homes and businesses in the city.

3. In 1917, the Battle of Verdun began in France, and several Pennsylvania regiments were among the American troops sent to fight in the conflict. Over 1,600 Pennsylvanian soldiers were killed or wounded during the battle.

4. In 1938, the Greater Pittsburgh International Airport (now Pittsburgh International Airport) opened. The airport was built to replace an outdated and overcrowded facility in downtown Pittsburgh and served as a hub for several airlines throughout the mid-20th century.

5. In 1944, the Hanford Site in Washington State began production of plutonium for use in the atomic bomb. The site was managed and operated by the DuPont Corporation, whose headquarters were in Wilmington, Delaware, just across the border from Pennsylvania. Many Pennsylvanians were employed at the site during World War II.