Wealth and Migration in Massachusetts and Maine: 1771–1798
利用家谱数据库，研究了美国建国初期边疆作为“安全阀”的作用，发现中产阶级而非穷人更善于利用边疆机会。
We use a genealogical data base to question the idea that the frontier was a “safety valve” for Americans in the years of the founding of the republic. Our findings about the relative wealth of members of nine families show how the frontier affected their migration patterns. We find that it was the middle class, not the poor, who seemed to make best use of the opportunity of the frontier.