The point at which a child becomes an adolescent is defined by the onset of puberty or by the beginning of the teenage stage. Adolescence is also viewed as ending with the teenage stage. However, in some individuals (particularly females), puberty begins in the preadolescence years.
Grundy County, Illinois. Grundy County is a county located in the U.S. state of Illinois. According to the 2010 census, it has a population of 50,063. Its county seat is Morris. Grundy County is part of the Chicago-Naperville-Elgin, IL-IN-WI Metropolitan Statistical Area.
St. Clair County is the oldest county in the U.S. state of Illinois. According to the 2010 census, it had a population of 270,056, making it the eighth most populous county in Illinois and the most populous in the southern portion of the state. Its county seat is Belleville. The county was founded in 1790, before the establishment of Illinois itself, and contains the historic French settlement and former mission, Cahokia Village, founded 1697.