Legislation enacted by the English Parliament to prevent foreign merchant vessels competing on equal terms with English ships. The earliest Act goes back to the reign of Richard II, but the most important was that of 1651, requiring that goods entering England must be carried in either English ships or ships of the country where the goods originated. Its aim was to destroy the Dutch carrying trade and it provoked the Anglo-Dutch Wars. The Acts applied to the colonies and despite the impetus they gave to New England shipping, they were widely resented in North America because of their increasingly strict measures against smugglers and against the colonial manufacture of certain goods that competed with English products. They were modified in 1823 and withdrawn in 1849.