What early colonial prosperity there was resulted from trapping and trading in furs. In addition, fishing was a primary source of wealth in Massachusetts. But throughout the colonies, people lived primarily on small farms and were self-sufficient. In the few small cities and among the larger plantations of North Carolina, South Carolina, and Virginia, some necessities and virtually all luxuries were imported in return for tobacco, rice, and indigo (blue dye) exports. Supportive industries developed as the colonies grew. A variety of specialized sawmills and gristmills appeared. Colonists established shipyards to build fishing fleets and, in time, trading vessels. The also built small iron forges. By the 18th century, regional patterns of development had become clear: the New England colonies relied on ship-building and sailing to generate wealth; plantations (many using slave labor) in Maryland, Virginia, and the Carolinas grew tobacco, rice, and indigo; and the middle colonies of New York, Pennsylvania, New Jersey, and Delaware shipped general crops and furs. Except for slaves, standards of living were generally high -- higher, in fact, than in England itself. Because English investors had withdrawn, the field was open to entrepreneurs among the colonists. By 1770, the North American colonies were ready, both economically and politically, to become part of the emerging self-government movement that had dominated English economics since the time of James I (1603-1625). Disputes developed with England over taxation and other matters; Americans hoped for a modification of English taxes and regulations that would satisfy their demand for more self-government. Few thought the mounting quarrel with the English government would lead to all-out war against the British and to independence for the colonies. Like the English political turmoil of the 17th and 18th centuries, the American Revolution (1775-1783) was both political and economic, bolstered by an emerging middle class with a rallying cry of "unalienable rights to life, liberty, and property" -- a phrase openly borrowed from English philosopher John Locke's Second Treatise on Civil Government (1690). The war was triggered by an event 21