1. The first recorded earthquake in Massachusetts history occurred on May 22, 1761. It was felt in Boston, Cambridge, and other surrounding areas, and is estimated to have been around 5.5 on the Richter scale.

2. On May 22, 1856, Congressman Preston Brooks of South Carolina brutally attacked Senator Charles Sumner of Massachusetts with a cane in the Senate chamber. The attack was motivated by Sumner's opposition to slavery and his criticism of Brooks' cousin, Senator Andrew Butler of South Carolina.

3. The Boston Celtics won their first NBA championship on May 22, 1957, defeating the St. Louis Hawks in a 7-game series. The team was led by future Hall of Famers Bill Russell and Bob Cousy.

4. On May 22, 1969, Harvard University and Radcliffe College announced the creation of Harvard-Radcliffe College, which would unite the two institutions under one undergraduate program. The merger was completed in 1977.

5. The Mohegan Sun casino opened in Uncasville, Connecticut, just a short drive from the Massachusetts border, on May 22, 1996. The casino complex includes a sprawling complex of hotels, restaurants, and entertainment venues, and boasts one of the largest gaming floors in the world.