1. The Boston Massacre occurred on March 20, 1770. The incident, which resulted in the killing of five colonists by British soldiers, became a pivotal moment in the lead up to the American Revolutionary War.

2. The first public baseball game in the United States was played in Pittsfield, Massachusetts on March 20, 1791. The game was played between the Berkshire Baseball Club and the Knickerbocker Baseball Club of New York City.

3. The Massachusetts State House was dedicated on March 20, 1798. The iconic building, located in Boston, has served as the home of the Massachusetts state government for over 200 years.

4. On March 20, 1852, Harriet Beecher Stowe published "Uncle Tom's Cabin," a novel that helped to change the public's perception of slavery and became a major factor in the lead up to the Civil War.

5. The first public reading of the Declaration of Independence in Massachusetts occurred on March 20, 1776 in Worcester. The document was read aloud in the town square by Isaiah Thomas, a printer and newspaper publisher who had become a prominent supporter of the revolution.