1. In 1639, the first militia in America, the Swedish Colonial Militia, was established in Fort Christina, now present-day Wilmington, Delaware. The militia was formed to safeguard the Swedish colony in the New World and to aid in the defense against the Native American population.

2. In 1799, George Washington's estate, Mount Vernon, was sold at auction to a group of wealthy businessmen, including Pennsylvania native Benjamin Chew. The estate had fallen into financial ruin after Washington's death, and the sale helped to pay off the considerable debt that he had accrued during his lifetime.

3. In 1907, Pennsylvania Governor Edwin S. Stuart signed a bill creating the State Forestry Reservation Commission, which was responsible for managing and protecting the state's forest lands. The commission later became the Pennsylvania Department of Conservation and Natural Resources, which is still in operation today.

4. In 1948, the Pittsburgh Symphony Orchestra performed its first concert in the newly-built Heinz Hall for the Performing Arts. The concert was conducted by Fritz Reiner and featured works by Wagner, Beethoven, and Richard Strauss.

5. In 2013, the Pennsylvania Supreme Court struck down a law that required voters to show photo identification at the polls. The court ruled that the law violated the state constitution's guarantee of free and equal elections, and that it would unfairly burden certain groups of voters, including minorities and the elderly.