For nearly two decades historians have argued that southern New England became an overcrowded society in the mid-eighteenth century. Population growth, soil depletion and the closing of the frontier in western Connecticut and Massachusetts diminished economic opportunity sufficiently to cause major dislocations and demographic readjustments. Hard data exist to show a large migration of southern New Englanders to New York, New Hampshire and Vermont in the Revolutionary era, and to the new West in the 1790s and afterwards. Although less conclusive and the subject of some debate, much other data suggest an increase in poverty, a decline in birth rates, as well as a correlation between political and religious unrest and declining economic opportunity. Much of this research was, of course, implicitly anticipated by the work of Frederick Jackson Turner: his view of the frontier as a "safety valve" for the East so obviously presupposes the conclusions of the new social historians that one has to wonder in retrospect why the overcrowding thesis seemed so iconoclastic in the 1960s when it was first articulated.1