The following dissertation adds to the literature on income convergence and population growth in the United States. It also expands knowledge on the relatively underexplored geography – the American micropolitan area. The study identifies determinants of changes in Economic Prosperity and Population Growth, as operationalized by Relative Per Capita Income and Percentage Population Growth in a sample of more than 500 micropolitan areas in the United States between 2002 and 2014. These micropolitan areas are relatively newly defined, county-based statistical areas built around small urban cores of 10,000 to 50,000 people. The study finds no evidence of income convergence during this time period in micropolitan areas. Other findings include: Proximity to a metropolitan area of 250,000 or more population predicted population growth for micropolitan areas, but relative income growth was higher in micropolitan areas more than 120 miles from larger metro areas. Relative Per Capita Personal Income grew faster in non-South Atlantic Region micropolitan areas than in the South Atlantic, but population growth in micropolitan areas was more likely in the South Atlantic region than in other regions. Manufacturing and Professional Services industry growth strongly predicted relative income growth. The dissertation concludes with qualitative analysis of outlier micropolitan areas and recommends future areas of study.