1. In 1969, astronaut Neil Armstrong became the first person to walk on the moon during the Apollo 11 mission. Armstrong was born in Wapakoneta, Ohio, but his famous phrase, "That's one small step for man, one giant leap for mankind," was heard around the world and has become a part of Pennsylvania's history.

2. In 1793, yellow fever broke out in Philadelphia, leading to one of the deadliest epidemics in American history. The city's residents fled in droves, but some brave individuals stayed behind to care for the sick and dying. The epidemic ultimately claimed the lives of over 5,000 people in the city.

3. July 20, 1863 marked the third day of the Battle of Gettysburg during the Civil War. The Confederate army made a final, desperate attack on Union forces at Cemetery Ridge, but they were repulsed with heavy losses. This battle is widely considered one of the turning points of the war.

4. In 1957, the Pennsylvania Railroad formally opened its world-famous Penn Station in New York City. The station was designed by the architectural firm of McKim, Mead & White, and became an iconic symbol of American railway travel.

5. In 1998, a tornado ripped through the town of St. Peter's in southeastern Pennsylvania, killing three people and injuring dozens more. The twister was part of a larger outbreak that struck the region, leaving a path of destruction in its wake.