1. Independence Hall Closed: One interesting fact about September 7 in Pennsylvania history is that on this day in 1788, Independence Hall in Philadelphia was closed to the public for the first time. The building was being used by the State of Pennsylvania and was closed for repairs.

2. Great Pittsburgh Fire: September 7, 1845, marked the start of the Great Pittsburgh Fire. The fire began in a small cabinet shop and quickly spread due to strong winds that day. The fire destroyed over 1,000 buildings and caused over $6 million in damage.

3. Scranton Rail Strike: In 1902, September 7 marked the end of the famous Scranton Rail Strike. The strike lasted for over two months and was one of the largest strikes in American history. It involved over 10,000 miners and laborers who were protesting against low pay and dangerous working conditions.

4. Philadelphia Eagles Win Super Bowl LII: On September 7, 2017, the Philadelphia Eagles won Super Bowl LII, defeating the New England Patriots 41-33. It was the first Super Bowl win in the team's history.

5. Johnstown Flood: On September 7, 1889, one of the deadliest floods in American history occurred in Johnstown, Pennsylvania. The flood was caused by the catastrophic failure of the South Fork Dam, which released 20 million tons of water into the valley below. Over 2,200 people died in the disaster, and it remains one of the worst natural disasters in American history.