Less noticed at the time, but scarcely less important in its effects upon trade and industry, was the law passed by Parliament in the same year for regulating colonial currency. With the rapid development of commerce in the eighteenth century, and on account of the steady flow of specie to London, the colonies had commonly resorted to the use of paper money as a legal tender in the payment of local debts. Such men as Franklin and Colden defended the practice on the ground of necessity, and it was undoubtedly true that without the issue of new bills of credit the colonies could not have given the military assistance required of them for the conquest of Canada. But it was equally true that in most colonies, except Massachusetts where the issues had been retired in 1749, and New York where their par value had been consistently maintained, the evils of depreciated currency had long existed and still went unremedied. Debtors profited at the expense of creditors, while colonial assemblies often took advantage of the situation to pass laws enabling the American trader to avoid meeting his just obligations to English merchants. In response to the loud complaints of the latter, and without adequately discriminating between the uses and the abuses of a colonial paper currency, Parliament passed the act "to prevent paper bills of credit hereafter issued in any of his Majesty's colonies, from being declared to be a legal tender in payment of money, and to prevent the legal tender of such bills as are now subsisting, from being prolonged beyond the periods limited for calling in and sinking the same." Meanwhile, the Ministry of Grenville had already turned to the problem of defense, so inseparably connected with the question of Indian relations and Western settlement. The English Government had long recognized the necessity of securing the friendship of the Indians; and to this end it had fostered the settlement of the interior. Indian traders, employing methods none too scrupulous, had been encouraged to ply their traffic beyond the mountains. Many thousands of acres of land had been granted, to individuals and to companies of promoters, in the belief that "nothing can more effectively tend to defeat the dangerous designs of the French," or better enable the English "to cultivate a friendship and carry on a more extensive commerce with the Indians inhabiting those parts." It was a policy which all Americans could understand. To those colonists who had fought with Washington to beat back the tide of Indian massacre, to those who had witnessed the destruction of Fort Duquesne, the conquest of Canada had no meaning unless it opened the great West to free settlement. And during the latter years of the war, thousands of families in all the old provinces were prepared, as Franklin said, "to swarm," while many hundreds had crossed the mountains and were already seated in the upper valleys of the Ohio.