<P> In the South, the poor lands were held by poor white farmers, who generally owned no slaves . The best lands were held by rich plantation owners, were operated primarily with slave labor . They grew their own food, and concentrated on a few crops that could be exported to meet the growing demand in Europe, especially cotton, tobacco, and sugar . The main export crop was cotton . But after a few years, the fertility of the soil was depleted and the plantation was moved to the new land further west . Much land was cleared and put into growing cotton in the Mississippi valley and in Alabama, and new grain growing areas were brought into production in the Mid West . Eventually this put severe downward pressure on prices, particularly of cotton, first from 1820--23 and again from 1840 - 43 . Sugar cane was being grown in Louisiana, where it was refined into granular sugar . Growing and refining sugar required a large amount of capital . Some of the nation's wealthiest men owned sugar plantations, which often had their own sugar mills . </P> <P> In New England, subsistence agriculture gave way after 1810 to production to provide food supplies for the rapidly growing industrial towns and cities . </P> <P> On the West Coast, beginning in the mid-1700s, Spanish missions in California spread Christianity among the Native Americans, and also transferred European agricultural techniques . The Spanish also introduced domesticated animals including Churro sheep, which were then farmed by some indigenous tribes . </P> <P> A dramatic expansion in farming took place from 1860 to 1910 . The number of farms tripled from 2 million in 1860 to 6 million in 1905 . The number of people living on farms grew from about 10 million in 1860 to 22 million in 1880 to 31 million in 1905 . The value of farms soared from $8 billion in 1860 to $30 billion in 1906 . </P>

Where did new england colonies begin to export their food crops