the racial and ethnic makeup of the American people is in flux. New immigrants from Asia and Latin America have added a large measure of cultural and phenotypic diversity to the American population in recent decades, just as waves of immigrants from Southern and Eastern Europe did a century ago (Bean and Stevens 2003; Higham 1988; Lieberson and Waters 1988: Ch. 2; Thompson and Whelpton 1933: Ch. 2). Moreover, the boundaries between racial and ethnic groups are becoming blurred by high rates of intermarriage and the growing number of persons with mixed ancestry (Lee and Bean 2004).