Kingsblood Royal by Sinclair Lewis

It was not that Winthrop and Thankful were much less black than their father, or had straighter hair or beakier noses, but they had even more assurance as American citizens. The easy confidence with which they looked at Neil, the straightness with which they carried their shoulders, made them seem not like products of the slave- block and the cotton-field, but like what they were--American school children, unusual only in unusual gentleness.

You cannot hear constantly at school that Americans are the bravest, richest and most generous people in history without absorbing a certain pride, which is not too objectionable if it be tempered by a more serene and informed culture at home.