23. NEW SCHEMES OF COLONIAL CONTROL (1763). [Sidenote: Grenville's colonial policy.] Allusion has already been made (§ 19) to vague schemes of colonial control suggested during the war. More serious measures were impending. When George Grenville became the head of the cabinet, in April, 1763, he took up and elaborated three distinctly new lines of policy, which grew to be the direct causes of the American Revolution. The first was the rigid execution of the Acts of Trade; the second was the taxation of the colonies for the partial support of British garrisons; the third was the permanent establishment of British troops in America. What was the purpose of each of these groups of measures? [Sidenote: Navigation acts.] [Sidenote: Effect of the system.] The object of the first series was simply to secure obedience to the Navigation Acts (Colonies, Section 44, 128),--laws long on the statute book, and admitted by most Americans to be legal. The Acts were intended simply to secure to the mother-country the trade of the colonies; they were in accordance with the practice of other nations; they were far milder than the similar systems of France and Spain, because they gave to colonial vessels and to colonial merchants the same privileges as those enjoyed by English ship-owners and traders. The Acts dated from 1645, but had repeatedly been re-enacted and enlarged, and from time to time more efficient provision was made for their enforcement. In the first place, the Navigation Acts required that all the colonial trade should be carried on in ships built and owned in England or the colonies. In the second place, most of the colonial products were included in a list of "enumerated goods," which could be sent abroad, even in English or colonial vessels, only to English ports. The intention was to give to English home merchants a middleman's profit in the exchange of American for foreign goods. Among the enumerated goods were tobacco, sugar, indigo, copper, and furs, most of them produced by the tropical and sub-tropical colonies. Lumber, provisions, and fish were usually not enumerated; and naval stores, such as tar, hemp, and masts, even received an English bounty. In 1733 was passed the "Sugar Act," by which prohibitory duties were laid on sugar and molasses imported from foreign colonies to the English plantations, Many of these provisions little affected the continental colonies, and in some respects were favorable to them. Thus the restriction of trade to English and colonial vessels stimulated ship- building and the shipping interest in the colonies. From 1772 to 1775 more than two thousand vessels were built in America. [Sidenote: Illegal trade.] [Sidenote: Difficulty of enforcement.]