Gang activity in the United States has been traced to the early 19th century when youth gangs emerged from some immigrant populations. Now, as then, gangs provide identity and social relationships for some young people who feel marginalised by the dominant social, economic and cultural environments in which they live. Gangs, however, are not simply a "street family" to some of the nation's disenfranchised. As distinguished by the U.S. Department of Justice, "a group must be involved in a pattern of criminal acts to be considered a youth gang." Between 1980 and 1996, the U.S. experienced significant growth in youth gangs, when the number of cities and jurisdictions that reported gang problems rose from 2863 to approximately 4,800. From 1996 through 1998, the growth seemed to slow down, but according to the 1999 National Youth Gang Survey, the number of gang members is again on the rise.