Boston Port Act

The Boston Port Act, passed by the British Parliament and becoming law on March 31, 1774, is one of the measures (variously called the Intolerable Acts, the Punitive Acts or the Coercive Acts) that were designed to secure the United Kingdom'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.

In other words, it closed Boston Port to all ships, no matter what business the ship had.