William G. Nagel studied crime across American States and found no relation between crime rates and incarceration rates. He concluded that crime depends on poverty, unemployment, and urbanization. He also asserted that imprisonment policies respond to States' political climates and the relative sizes of their black populations. Nagel's research may have received less attention than it deserved because he was not a social scientist. However, reanalysis of his data, with adjustments to certain methodological areas, produces support for his conclusions. The reanalysis strongly supports Nagel's central point that incarceration as the main approach to crime does not reduce it. However, Nagel's emphasis on political climate as a second determinant of prison construction is not supported. Nevertheless, the data show that unemployment is the most important determinant of crime. For a State with a population of 4 million, a 1 percent decline in unemployment would prevent more than 10,000 Index crimes per year. Data tables, notes, and 13 references are provided.