Massachusetts General Laws Part I. Administration of the Government (Ch. 1-182) Ch. 6, § 12D

The governor shall annually issue a proclamation calling for a proper observance on March fifth of the anniversary of the Boston Massacre wherein Crispus Attucks, an American of African descent, and Samuel Maverick, James Caldwell, Samuel Gray and Patrick Carr met heroic deaths as the first martyrs in the cause of American independence.