1. Pennsylvania became the second state to ratify the United States Constitution on September 27, 1787. This pivotal moment in Pennsylvania history paved the way for the formation of the federal government and the establishment of the United States as a nation.

2. On September 27, 1777, the Battle of Germantown was fought in Pennsylvania during the American Revolutionary War. This battle was fought between American forces led by General George Washington against British forces. Although the American forces were ultimately defeated, the battle demonstrated their ability to hold their own against the powerful British army.

3. September 27, 1928, marked the completion of the Pennsylvania Turnpike, which was the first long-distance paved highway in the United States. This major transportation infrastructure project connected Pittsburgh and Harrisburg, Pennsylvania, and became a model for future highway construction projects throughout the country.

4. The Carnegie Museum of Natural History in Pittsburgh, Pennsylvania, opened its doors to the public on September 27, 1895. This world-renowned museum is home to over 22 million specimens and artifacts, and it has received numerous accolades for its research and education programs.

5. September 27, 1779, was the date of the infamous Wyoming Valley massacre, which took place in northeastern Pennsylvania during the American Revolutionary War. British forces and their Native American allies attacked a civilian settlement, killing over 300 men, women, and children. The massacre was one of the deadliest acts of violence against civilians during the Revolutionary War.