An example of chain migration in the US is the following:
María, a legal immigrant from Mexico, is living in the US with her husband and two children. She sponsors her sister, Juana, to immigrate to the US. Upon Juana's arrival, Juana lives with María's family while she gets settled and finds a job. Juana eventually sponsors her own husband and children to immigrate, too. Eventually, her adult children sponsor members of their own families for immigration, extending the chain.