An analysis of U.S. counties whose populations reached one million or more between 1960 and 2010, totaling 41, revealed high levels of population volatility (US Census Bureau: 1960 Census, 1970 Census, 1980 Census, 1990 Census, 2000 Census, 2010 Census). Throughout all four regions—Northeast, Midwest, South, and West—a wide range of population growth patterns were discovered over the 50-year period, both between and within regions, deserving serious consideration by policymakers. Rapid, unsustainable growth in booming counties can be as worrisome as declining tax bases in counties where population has contracted. Regardless of interregional and intraregional heterogeneity, several trends span the nation. In all regions, suburban sprawl has resulted in decentralized populations and economies in most metropolitan areas. Suburban counties have experienced greater population growth than metropolitan core counties, as seen in the New York metropolitan area, where minimal growth in New York City’s five counties was dwarfed by that of neighboring suburban Suffolk County. In the Northeast, where population density has traditionally been high, a majority of large counties experienced declining populations. Allegheny (Pittsburgh) and Philadelphia contracted 25 % by 2010. The sharpest decline in the Northeast occurred during the 1970s due to declining steel industries located in these areas, as well as racial and cultural conflicts (Boskin, J., Annals of the American Academy of Political and Social Science, 1969). After 1980, most large metropolitan counties in the region Int Adv Econ Res (2013) 19:321–323 DOI 10.1007/s11294-013-9413-4