1. In 1682, William Penn arrived in Pennsylvania, which he had just acquired from the British Crown. He named the land "Sylvania" (meaning "woodland"), but King Charles II added "Penn" to recognize the work that Penn's father had done for the Crown.

2. In 1777, during the American Revolutionary War, British forces led by General William Howe captured Philadelphia, forcing the Continental Congress to flee the city. The British occupation lasted for nearly a year, until they were defeated at the Battle of Monmouth in 1778.

3. In 1847, the first medical school for women in the United States, the Female Medical College of Pennsylvania, was established in Philadelphia. The school would later merge with another medical school and become the Women's Medical College of Pennsylvania, which operated until 1970.

4. In 1927, the first transatlantic telephone call was made between New York City and London. The call was made using a new technology called "radio telephony," which allowed for voice communication over the radio waves.

5. In 2005, the Pennsylvania Supreme Court ruled that the state's law banning same-sex marriage was unconstitutional. The ruling paved the way for the legalization of same-sex marriage in Pennsylvania in 2014, when another court struck down the state's ban.