1. On May 22, 1776, a conference was held in Philadelphia to discuss Pennsylvania's position in the emerging American Revolution. The conference resulted in the formation of the Committee of Safety, which coordinated military efforts against the British.

2. On May 22, 1856, the first Republican State Convention in Pennsylvania was held in Harrisburg. The convention was attended by over 1,000 delegates and marked the beginning of the Republican Party's dominance in Pennsylvania politics.

3. On May 22, 1933, the Pennsylvania Turnpike Commission was established to oversee the construction of the Pennsylvania Turnpike. The turnpike, which opened in 1940, was the first long-distance highway in the United States and revolutionized the way people traveled.

4. On May 22, 1950, the Philadelphia Phillies played their first night game at Shibe Park. The game, which was against the Boston Braves, attracted a crowd of over 18,000 fans and marked the beginning of a new era in baseball.

5. On May 22, 1972, the Great Flood of 1972 struck Pennsylvania, causing widespread damage and claiming the lives of 76 people. The flood was caused by heavy rain from the remnants of Hurricane Agnes and remains one of the worst natural disasters in Pennsylvania history.