Jail construction has vastly expanded America’s capacity to incarcerate people. In 1970, there were 243,000 jail beds in the United States, but by 2017, there were 915,100. This report explores the persistence of jail expansion by examining a convenience sample of 77 counties in 31 states that considered or pursued jail expansion between 2000 and 2019. From this sample, Vera researchers identified three major arguments county officials make to support construction: health and safety concerns due to overcrowding or aging facilities; the need to provide specialized services, including mental health and drug treatment; and the opportunity for revenue from renting beds to other authorities. The report also outlines negative or unanticipated consequences counties experienced from the decision to build or expand and provides examples of places that have pursued better alternatives to new jails.