Such, in outline, was the government originated for Virginia by the liberal leaders of the London Company, and put into operation by Sir George Yeardley. It lasted, with the short intermission of the Commonwealth Period, for more than one hundred and fifty years, and under it Virginia became the most populous and wealthy of the English colonies in America. The successful cultivation of tobacco in Virginia, as we have seen, put new life into the discouraged London Company. The shareholders, feeling that now at last the colony would grow and prosper, exerted themselves to the utmost to secure desirable settlers and to equip them properly. Soon fleets of considerable size were leaving the English ports for America, their decks and cabins crowded with emigrants and their holds laden with clothing, arms and farming implements.[150] During the months from March 1620 to March 1621 ten ships sailed, carrying no less than 1051 persons.[151] In the year ending March, 1622, seventeen ships reached Virginia, bringing over fifteen hundred new settlers.[152] And this stream continued without abatement until 1624, when disasters in Virginia, quarrels among the shareholders and the hostility of the King brought discouragement to the Company. In all, there reached the colony from November, 1619, to February, 1625, nearly five thousand men, women and children.[153] Although tobacco culture was the only enterprise of the colony which had yielded a profit, it was not the design of Sandys and his friends that that plant should monopolize the energies of the settlers. They hoped to make Virginia an industrial community, capable of furnishing the mother country with various manufactured articles, then imported from foreign countries. Especially anxious were they to render England independent in their supply of pig iron. Ore having been discovered a few miles above Henrico on the James, a furnace was erected there and more than a hundred skilled workmen brought over from England to put it into operation. Before the works could be completed, however, they were utterly demolished by the savages, the machinery thrown into the river, all the workmen slaughtered,[154] and the only return the Company obtained for an outlay of thousands of pounds was a shovel, a pair of tongs and one bar of iron.[155] Efforts were made later to repair the havoc wrought by the Indians and to reëstablish the works, but they came to nothing. Not until the time of Governor Spotswood were iron furnaces operated in Virginia, and even then the industry met with a scant measure of success.