1. Boston Tea Party Debates (1773): On March 15, 1773, a town meeting was held at Faneuil Hall in Boston to debate whether or not to allow the tea ships of the British East India Company to dock and unload their cargo. This meeting was part of a series of events that ultimately led to the famous Boston Tea Party.

2. Constitution Ratification (1781): On March 15, 1781, the Massachusetts State Legislature ratified the Articles of Confederation. This made Massachusetts the sixth state to ratify the articles, which served as the governing document of the United States until the ratification of the Constitution in 1788.

3. Incorporation of Cambridge (1846): On March 15, 1846, the Massachusetts state legislature approved the incorporation of Cambridge as a city. Prior to this, Cambridge had been a town within Middlesex County.

4. Birth of John J. Pershing (1860): On March 15, 1860, General John J. Pershing was born in Laclede, Missouri. Pershing was a military commander during World War I and is perhaps best known for his leadership of American forces in Europe during that conflict.

5. Boston Irish Evacuation (1776): In March of 1776, General George Washington ordered the evacuation of Boston by the British forces that had been occupying the city. The evacuation took place on March 17, but preparation for it began on March 15. This event is commemorated in Boston each year on St. Patrick's Day, which falls on March 17.