In North America, potash making quickly became an adjunct to the clearing of land for agriculture, for it was estimated that as much as half the cost of clearing land could be recovered by the sale of potash. Some potash was exported from Maine and New Hampshire in the seventeenth century, but the market turned out to be mainly domestic, consisting mostly of shipments from the northern to the southern colonies. For despite the beginning of the trade at Jamestown and such encouragements as a series of acts to encourage the making of potash, beginning in 1707 in South Carolina, the softwoods in the South proved to be poor sources of the substance.