The Boston Port Act, passed by Britain's Parliament and becoming law on 31 March 1774, is one of the measures (variously called the Intolerable Acts, the Punitive Acts or the Coercive Acts) that were designed to secure Britain's jurisdictions over her American dominions.
A response to the Boston Tea Party, it outlawed the use of the Port of Boston for "landing and discharging, lading or shipping, of goods, wares, and merchandise" until such time as restitution was made to the King's treasury (for customs duty lost) and to the East India Company for damages suffered.