Wampum's dramatic transformation in the late sixteenth and early seventeenth centuries demonstrates clearly the effects of the fur trade on the northeast Indians' socioeconomic system. Made of carefully ground whelk and quahog shells found only in Long Island Sound, strings of purple and white wampum did not function as currency in precontact North America. Rather, as the historian William Cronon points out, these high-prestige items served as an important "medium of gift giving" that conformed to the Native Americans' system of reciprocal social relations. So prized were wampum beads, in fact, that they were exchanged as gifts only for important purposes such as paying restitution for a murder, offering tribute to a powerful chief, or consummating an alliance with a foreign tribe.

The arrival of Europeans and the consequent integration of the Indians into the Atlantic economy through the fur trade rapidly transformed wampum's nature...