To understand the American Revolution, therefore, several facts must be clearly in mind--first, that Great Britain had for one hundred and fifty years been growing to the dignity of an empire, and that the thirteen colonies were a considerable part of that empire; second, the colonies had interests of their own which were not favored by the growing size and strength of the empire. They were advancing to new political ideals faster than the mother-country. Their economic interests were becoming differentiated from those of England. They were coming to have wants and ambitions and hopes of their own quite distinct from those of Great Britain. At the fatal time when the independent spirit of America had grown assertive, the politically active part of the British people began unconsciously to favor an imperial policy, which their ministers suggested, and which to them seemed the very essence of sound reasoning and good government. They approved of the proposed creation of executives who should be independent of the dictation of the colonial assemblies. There were also to be new administrative organs having power to enforce the colonial trade regulations; and the defensive system of the colonies was to be improved by a force of regular troops, which was in part to be supported by colonial taxes. In order to accomplish these objects, the king’s new minister, the assiduous Grenville, who knew the law better than the maxims of statesmanship, induced Parliament, in March, 1764, to resolve upon “certain stamp duties” for the colonies. A year later the “Gentle Shepherd,” as Pitt had dubbed him, proved his watchfulness by getting a stamp act passed,[45] which, though nearly a duplicate of one in force in England, and like one of Massachusetts’ own laws, nevertheless aroused every colony to violent wrath. This sudden flame of colonial passion rose from the embers of discontent with Grenville’s policy of enforcing the trade or navigation laws--those restrictions upon colonial industries and commerce which were the outgrowth of a protective commercial policy which England had begun even before the discovery of America.[46] As the colonies grew they began to be regarded as a source of wealth to the mother-country; and, at the same time that bounties were given them for raising commodities desired by England, restrictions were placed upon American trade.[47] When the settlers of the northern and middle colonies began manufacturing for themselves, their industry no sooner interfered with English manufactures than a law was passed to prevent the exportation of the production and to limit the industry itself. This system of restrictions, though it necessarily established a real opposition of interest between America and England, does not seem on the whole to have been to the disadvantage of the colonies;[48] nor was the English colonial system a whit more severe than that of other European countries.