Responses, after the initial mailing and a followup, were received from 48 States. Data indicated that inmate populations exceeded design capacity in 40 States, and in States not exceeding design capacity, inmate populations ranged from 95- to 100-percent capacity. Total population was at 131.6-percent capacity. New construction of prisons and cell blocks was the predominant administrative response to overcrowding, reported by 83.3 percent, while increased use of community-based facilities was reported by 68.8 percent. Data are detailed for conversion of existing prison space, other administrative responses, and new construction. Responses to overcrowding that reduce the number of inmates sentenced to prison appear to be most economical and promising.