During the first seven decades of the English fur trade in the middle Connecticut River valley of Massachusetts, the Pocumtuck, Nonotuck, Sokoki, and other Native American tribal nations were densely documented and actively engaged in intercultural trade, diplomacy, and conflict. Amid the increasing hostilities of the 1670s to the mid-1700s, the valley's Native people largely folded into the populations of surrounding tribes, and documentation on them diminished. During the 1800s, Deerfield historian George Sheldon depicted this complex history as an Indian vanishing act and refused to acknowledge the presence of living Native descendants.