This paper examines changes in urban sprawl in United States metropolitan areas from 1970 to 2010 using a sprawl measure based on the proportional differences in population percentages between high density and low density tracts. During the past four decades, sprawl has increased, but the rate of increase has dramatically decelerated since the 1970s. Considering individual metropolitan areas, there are several different sprawl histories. Some metros continue to have high rates of sprawl increases, others (the majority) have settled into steady state or modestly changing levels of sprawl, and others have a history of densification. Regression analysis shows that 1970 sprawl levels, western location, median household income, center city population change, African American and Hispanic population percentages, southern location and percent of the workforce employed in manufacturing were associated with changes between 1970 and 2010 sprawl levels. These divergent trajectories, along with a closer examination of sprawl in individual metropolitan areas, suggest sprawl may be neither inevitable nor irreversible.