1. In 1861, the first shot was fired in the American Civil War, marking the beginning of four years of conflict that would reshape the nation. The attack on Fort Sumter, located in Charleston Harbor, South Carolina, was led by Confederate troops under the command of General P.G.T. Beauregard.

2. In 1907, the Monongahela Street Railway Company, a streetcar company serving the Pittsburgh area, installed the first automatic electric track switch. This innovation allowed streetcars to be directed onto different tracks at intersections, improving the efficiency and safety of the system.

3. In 1947, the United States government announced that it would open a new Naval Supply Depot in Mechanicsburg, Pennsylvania. The facility, which would eventually become known as the Defense Distribution Center, played a key role in supplying military operations around the world.

4. In 1961, the Allenberry Playhouse in Boiling Springs, Pennsylvania, opened for its first season of summer stock theater. Over the years, the theater has hosted numerous well-known actors and productions, including a young Kevin Bacon in a production of "Jesus Christ Superstar" in 1973.

5. In 2014, Governor Tom Corbett signed a law legalizing medical marijuana in Pennsylvania, making it the 24th state to do so. The law allows patients with certain medical conditions to use marijuana to treat their symptoms, but it does not permit recreational use of the drug.