1. Philadelphia becomes a city: On March 26, 1701, William Penn signed a charter officially making Philadelphia a city. Penn, a Quaker and owner of the Pennsylvania colony, named the city after the Greek words for “brotherly love.” Philadelphia quickly became an important center of commerce and culture in the young United States.

2. The first Presbyterian minister is ordained: On March 26, 1703, Francis Makemie was ordained as the first Presbyterian minister in the United States. Born in Ireland, Makemie helped establish the Presbyterian Church in Virginia and Maryland.

3. The Pennsylvania Railroad is incorporated: On March 26, 1846, a group of businessmen met in Philadelphia to incorporate the Pennsylvania Railroad. The railroad would eventually span more than 10,000 miles and become one of the largest transportation companies in the world.

4. Hershey’s chocolate factory opens: On March 26, 1905, the Hershey’s chocolate factory opened in Hershey, Pennsylvania. The factory produced milk chocolate bars, Hershey’s Kisses, and other candies, and helped turn the small town of Hershey into a major tourist destination.

5. The deadliest mining disaster in U.S. history: On March 26, 1947, an explosion at the Centralia No. 5 coal mine in Illinois killed 111 miners. Many of the miners were from Pennsylvania, which was home to numerous coal mining communities. The disaster led to new safety regulations and sparked debates about the future of the coal industry.