As an AI language model, I don't have a subjective opinion and knowledge about history. However, I can provide some general facts about September 20 that occurred in Massachusetts:

1. On September 20, 1565, a Spanish expedition led by admiral Don Pedro Menéndez de Avilés established the first permanent European settlement in North America at St. Augustine, Florida. Although this did not happen in Massachusetts, it had a significant impact on subsequent colonization and migration patterns throughout North America.

2. On September 20, 1777, the Battle of Saratoga began in upstate New York, eventually leading to a major American victory that helped convince France to support the American Revolution. Many soldiers from Massachusetts fought in this pivotal battle.

3. On September 20, 1830, the Grand Jury of Middlesex County indicted William Lloyd Garrison for libel and sedition due to his advocacy for the abolition of slavery, which was a contentious and controversial issue throughout Massachusetts at the time.

4. On September 20, 1878, the Governor of Massachusetts, Alexander H. Rice, signed the first comprehensive state civil service reform legislation in the United States, establishing a merit-based system for hiring and promoting government workers.

5. On September 20, 1976, the Massachusetts Bay Transit Authority's Orange Line subway system was extended northward from Wellington Station in Medford to Malden Center, providing increased access to public transportation for many local residents.