They came on boats, on trains, great unceasing waves of them--the poor, the disenfranchised, the seekers, the dreamers. Second and third generations of farmers eking out an existence on scraps of farms divided up among too many sons. Political agitators no longer welcome in their homelands. Young men fleeing conscription in a king's army. Married couples starting out. Bachelors from towns with few women. The poor in tenements with air so stifling...