Juvenile courts are increasingly similar to criminal courts in their method as well as in their general atmosphere. State and Federal laws are being changed to send a growing number of young offenders to criminal court where they can be tried as if they were adults. The two court systems appear to be moving toward complete convergence. Policymakers and practitioners need to be aware of the factors leading to this convergence and they should understand the effects it may have on offenders, victims, and the general community. This chapter reviews the origins of juvenile justice in the United States, summarizes the legislative and policy changes that are effectively dismantling the juvenile-criminal border, and examines research on the impact of such policies. Published: July 2000 Volume 2 of Boundary Changes in Criminal Justice Organizations, pp. 167-213, Washington, DC: National Institute of Justice, U.S. Department of Justice, NCJ 182409.