1. On June 12, 1857, the first baseball convention was held in Harrisburg, Pennsylvania. The convention was attended by representatives from sixteen baseball clubs from various parts of the state. This convention was an important step in the early development of organized baseball in the United States.

2. June 12, 1893, marks the opening of the World's Columbian Exposition in Chicago. Pennsylvania played an important role in the Exposition, as it was home to many of the companies that showcased their products at the event. The Pennsylvania Railroad Company was also heavily involved in transporting people and goods to and from the fair.

3. On June 12, 1901, the first casket factory in the United States was established in Reading, Pennsylvania. The factory was owned by the Charles X. Reichert Casket Company, which would eventually become one of the largest casket manufacturers in the country.

4. June 12, 1946, saw the founding of the Tasty Baking Company in Philadelphia, Pennsylvania. The company is famous for products such as Tastykakes and Krimpets, which are still popular in the state today.

5. On June 12, 1978, the landmark Supreme Court case First National Bank of Boston v. Bellotti was decided. The case established that corporations have the right to spend money on political campaigns and issue advocacy, which has had a significant impact on political campaigns since. The case was brought by a group of citizens and organizations in Massachusetts who were concerned about corporate influence in elections.