Navigation Acts, in English history, name given to certain parliamentary legislation, more properly called the British Acts of Trade. The acts were an outgrowth ofmercantilism, and followed principles laid down by Tudor and early Stuart trade regulations. They had as their purpose the expansion of the English carrying trade, the provision from the colonies of materials England could not produce, and the establishment of colonial markets for English manufactures. The rise of the Dutch carrying trade, which threatened to drive English shipping from the seas, was the immediate cause for the Navigation Act of 1651, and it in turn was a major cause of the First Dutch War. It forbade the importation of plantation commodities of Asia, Africa, and America except in ships owned by Englishmen. European goods could be brought into England and English possessions only in ships belonging to Englishmen, to people of the country where the cargo was produced, or to people of the country receiving first shipment. This piece of Commonwealth legislation was substantially reenacted in the First Navigation Act of 1660 (confirmed 1661). The First Act enumerated such colonial articles as sugar, tobacco, cotton, and indigo; these were to be supplied only to England. This act was expanded and altered by the succeeding Navigation Acts of 1662, 1663, 1670, 1673, and by the Act to Prevent Frauds and Abuses of 1696. In the act of 1663 the important staple principle required that all foreign goods be shipped to the American colonies through English ports. In return for restrictions on manufacturing and the regulation of trade, colonial commodities were often given a monopoly of the English market and preferential tariff treatment. Thus Americans benefited when tobacco cultivation was made illegal within England, and British West Indian planters were aided by high duties on French sugar. But resentments developed. The Molasses Act of 1733, which raised duties on French West Indian sugar, angered Americans by forcing them to buy the more expensive British West Indian sugar. Extensive smuggling resulted. American historians disagree on whether or not the advantages of the acts outweighed the disadvantages from a colonial point of view. It is clear, however, that the acts hindered the development of manufacturing in the colonies and were a focus of the agitation preceding the American Revolution. Vigorous attempts to prevent smuggling in the American colonies after 1765 led to arbitrary seizures of ships and aroused hostility. The legislation had an unfavorable effect on the Channel Islands, Scotland (before the Act of Union of 1707), and especially Ireland, by excluding them from a preferential position within the system. Shaken by the American Revolution, the system, along with mercantilism, fell into decline. The acts were finally repealed in 1849.