Gangs have existed at least since the 14th century in Europe and in the colonial period in North America. However, deviant youth groups did not exist in any large number in the United States until the 19th century. Youth gangs and prison gangs have become closely related over the past several years. The National Major Gang Task Force was formed by correctional gang experts from several States and the Federal Bureau of Prisons to provide current information on gang activities and emerging trends across the Nation. The American Jail Association has co-hosted two seminars on gangs in jails. The desire to be in a gang reflects the natural human desire to want to belong to groups of people that provide support, companionship, and respect. Increasing numbers of youth lack family support and fulfill their needs through gangs. Jail personnel should identify inmates who are gang members as soon as possible and should be aware of gang names and identifying marks. At least 283 prison gangs, disruptive groups, or security threat groups are currently believed to exist. Photographs and table summarizing numbers of gang members and gang-related crimes