1. In 1783, the Continental Congress met at the Old State House in Philadelphia and signed the preliminary articles of peace, officially ending the Revolutionary War between Great Britain and the United States.

2. In 1861, the Civil War officially began with the seizure of Fort Sumter in South Carolina. Pennsylvania played a significant role in the war effort, with its soldiers making up nearly 10% of Union forces.

3. In 1898, the Spanish-American War began, with Pennsylvania sending over 17,000 troops to fight in the conflict. The war resulted in the acquisition of several territories by the United States, including Puerto Rico and Guam.

4. In 1901, the Pennsylvania Railroad opened its iconic Pennsylvania Station in Manhattan, which would become one of the busiest transportation hubs in the country for many years.

5. In 1992, the Philadelphia Flyers won their first game in the playoffs against the New York Rangers, with the deciding goal scored by Kevin Dineen in the second overtime. The Flyers would go on to win the series and advance to the Stanley Cup Finals.