14.1.4 to 14.1.6

Nearly all these early settlements arose from the enterprise of particular companies and magnates rather than from any effort on the part of the English crown. The crown exercised some rights of appointment and supervision, but the colonies were essentially self-managing enterprises. The formation of the empire was thus an unorganized process based on piecemeal acquisition, sometimes with the British government being the least willing partner in the enterprise. In the 17th and 18th centuries, the crown exercised control over its colonies chiefly in the areas of trade and shipping. In accordance with the mercantilist philosophy of the time, the colonies were regarded as a source of necessary raw materials for England and were granted monopolies for their products, such as tobacco and sugar, in the British market. In return, they were expected to conduct all their trade by means of English ships and to serve as markets for British manufactured goods. The Navigation Act of 1651 and subsequent acts set up a closed economy between Britain and its colonies; all colonial exports had to be shipped on English ships to the British market, and all colonial imports had to come by way of England. This arrangement lasted until the combined effects of the Scottish economist Adam Smith's Wealth of Nations (1776), the loss of the American colonies, and the growth of a free-trade movement in Britain slowly brought it to an end in the first half of the 19th century. The slave trade acquired a peculiar importance to Britain's colonial economy in the Americas, and it became an economic necessity for the Caribbean colonies and for the southern parts of the future United States. Movements for the end of slavery came to fruition in British colonial possessions long before the similar movement in the United States; the trade was abolished in 1807 and slavery itself in Britain's dominions in 1833.