migration always has been controversial in the United States. More than two centuries ago, Benjamin Franklin worried that too many German immigrants would swamp America’s predominantly British culture. In the mid-1800s, Irish immigrants were scorned as lazy drunks, not to mention Roman Catholics. At the turn of the century a wave of “new immigrants” — Poles, Italians, Russian Jews — were believed to be too different ever to assimilate into American life. Today the same fears are raised about immigrants from Latin America and Asia, but current critics of immigration are as wrong as their counterparts were in previous eras.