The manufacturers of Birmingham, on the other hand, petitioned that the bill was a benefit to their trade and to the colonists, who would exchange their raw products for British manufactures; that manufacturing was more valuable to the nation than the production of raw materials, and as iron could not be produced at home in such quantity and at such price as to supply all the needs of the manufacturers, it was the duty of Parliament to encourage the importation of raw materials, even if it should arrest their production in England; that the importation of iron from America could affect the iron works no more than the same quantity from any other country, and the home production was less than one-half the amount required, and growing steadily dearer: that the increasing activity of the English manufacturers rendered it more and more necessary to obtain these materials at the lowest price, and the only way to do this was either to reduce the duty on continental iron, or make it necessary for English iron masters to reduce their prices by raising up a rival in America. They heartily concurred, however, in the prohibition of all finishing of materials as an interference with British manufactures. The merchants of Bristol petitioned that American bar iron, which was admitted only at the port of London, be imported duty free into all of His Majesty’s ports. This discussion continued until 1757, when the privilege of importation was extended to the other ports of Great Britain.[112] [112] _Ibid._, Vol. I, pp. 626-627. Under the act of 1750, the importation rose to about 3250 tons, 94 per cent of which still came from Maryland, Virginia and Pennsylvania. Practically all the iron produced in New England was used there, for, despite the repressive measures from the mother country, small local manufacturing enterprises, “moonshine iron works,” were constantly cropping up. The iron supply of New England came at first from the bog ores in eastern Massachusetts and Rhode Island. By 1730-1760 better mines were opened at Salisbury, Conn., and in Orange County, New York, so that the production of iron in the bog-ore regions gradually dwindled. The Revolution terminated British legislative control over the trade and manufactures of America. The war itself furnished a market for supplies for the army, and the manufacture of cannon and guns was active. Many of these factories were ruined by the flood of imports which followed the Revolution. In 1789 the present Federal Government replaced the ineffective Confederation, which had left to the separate states the duty of protecting their manufacturing interests, and a tariff was placed upon manufactured articles. Freed from the old restrictions, and with foreign competition largely precluded, manufacturing industries began to spring up on every hand.