Boston Massacre Site is near Congress Dental Group in Boston MA. On March 5, 1770, the tension from the British military occupation of Boston escalated into the event now referred to as the Boston Massacre. The Boston Massacre site marker is located at the intersection of State and Congress Streets in Downtown Boston, outside of the Old State House, a few yards away from where the Massacre took place. The Massacre site has been moved twice, both times from the center of the intersection. Today, a medallion on the Freedom Trail marks the site of the Boston Massacre and reenactments hosted by the Bostonian Society take place on the anniversary every year.