<P> On the whole, the Acts of Trade and Navigation were obeyed, except for the Molasses Act 1733, which led to extensive smuggling because no effective means of enforcement was provided until the 1750s . Stricter enforcement under the Sugar Act 1764 became one source of resentment of Great Britain by merchants in the American colonies . This, in turn, helped push the colonies to start the American Revolution in the late 18th century, even though the consensus view among modern economic historians and economists is that the "costs imposed on (American) colonists by the trade restrictions of the Navigation Acts were small ." </P> <P> Some principles of English mercantile legislation pre-date both the passage of the 1651 navigation act and the settlement of its early foreign possessions . A 1381 act passed under King Richard II provided "that, to increase the navy of England, no goods or merchandises shall be either exported or imported, but only in ships belonging to the King's subjects ." The letters patent granted to the Cabots by Henry VII in 1498, stipulated that the commerce resulting from their discoveries must be with England, (specifically Bristol). Henry VIII established a second principle by statute, that such a vessel must be English - built and a majority of the crew must be English - born . Legislation during the reign of Elizabeth I also dealt with these questions and resulted in a large increase for English merchant shipping . Soon after actual settlements had been made in America, these early requirements illustrate the English theory then - held regarding the governmental control of maritime commerce . </P> <P> With the establishment of overseas colonies a distinct colonial policy began to develop, and the principles embodied in the early Navigation and Trade Acts also had some more immediate precedents in the provisions of the charters granted to the London and Plymouth Company, in the various royal patents later bestowed by Charles I and Charles II, as well as in the early regulations concerning the tobacco trade, the first profitable colonial export . An order in council of October 24, 1621, prohibited the Virginia colony to export tobacco and other commodities to foreign countries . The London Company lost its charter in 1624; the same year a proclamation, followed by orders in council, prohibited the use of foreign ships for the Virginia tobacco trade . These early companies held the monopoly on trade with their plantation; this meant that the developed commerce was to be England's . The Crown's purpose was to restrict for England the future commerce with America; it is well shown in the patent granted by Charles I to William Berkeley in 1639, by which the patentee was "to oblige the masters of vessels, freighted with productions of the colony, to give bond before their departure to bring same into England...and to forbid all trade with foreign vessels, except upon necessity ." </P> <P> As early as 1641 some English merchants urged that these rules be embodied in an act of Parliament, and during the Long Parliament, movement began in that direction . The Ordinance for Free Trade with the plantations in New England was passed in November 1644 . In 1645, to both conciliate the colonies and encourage English shipping, the Long Parliament prohibited the shipment of whalebone, except in English - built ships; they later prohibited the importation of French wine, wool, and silk from France; More generally and significantly on 23 January 1647, they passed the Ordinance granting privileges for the encouragement of Adventurers to plantations in Virginia, Bermudas, Barbados, and other places of America; it enacted that for three years no export duty be levied on goods intended for the colonies, provided they were forwarded in English vessels . Adam Anderson notes this law also included "security being given here, and certificates from thence, that the said goods be really exported thither. and for the only use of the said plantations;" He concludes: "Hereby the foundation was laid for the navigation acts afterward, which may be justly termed the Commercial Palladium of Britain ." </P>

The navigation acts enacted by the english parliament