The history bears this out. In 1856, Ralph Waldo Emerson delineated the significance of race:
It is race, is it not, that puts the hundred millions of India under the dominion of a remote island in the north of Europe. Race avails much, if that be true, which is alleged, that all Celts are Catholics, and all Saxons are Protestants; that Celts love unity of power, and Saxons the representative principle. Race is a controlling influence in the Jew, who, for two millenniums, under every climate, has preserved the same character and employments. Race in the negro is of appalling importance. The French in Canada, cut off from all intercourse with the parent people, have held their national traits. I chanced to read Tacitus "on the Manners of the Germans," not long since, in Missouri, and the heart of Illinois, and I found abundant points of resemblance between the Germans of the Hercynian forest, and our Hoosiers, Suckers, and Badgers of the American woods.
Indeed, Emerson in 1835, saw race as central to American greatness:
The inhabitants of the United States, especially of the Northern portion, are descended from the people of England and have inherited the trais of their national character...It is common with the Franks to break their faith and laugh at it The race of Franks is faithless.
Emerson was not alone, as historian James McPherson points out, Southerners not only thought of themselves as a race separate from blacks, but as a race apart from Northern whites:
The South's leading writer on political economy, James B. D. De Bow, subscribed to this Norman-Cavalier thesis and helped to popularize it in De Bow's Review. As the lower-South states seceded one after another during the winter of 1860-61, this influential journal carried several long articles justifying secession on the grounds of irreconcilable ethnic differences between Southern and Northern whites. "The Cavaliers, Jacobites, and Huguenots, who settled the South, naturally hate, contemn, and despise the Puritans who settled the North," proclaimed one of these articles. "The former are a master-race; the latter a slave race, the descendants of Saxon serfs." The South was now achieving its "independent destiny" by repudiating the failed experiment of civic nationalism that had foolishly tried in 1789 to "erect one nation out of two irreconcilable peoples."
Similarly, in 1899 William Z. Ripley wrote The Races of Europe, which sought to delineate racial difference through head-type:
The shape of the human head by which we mean the general proportions of length, breadth, and height, irrespective of the " bumps " of the phrenologist is one of the best available tests of race known. Its value is, at the same time, but imperfectly appreciated beyond the inner circle of professional anthropology. Yet it is so simple a phenomenon, both in principle and in practical application, that it may readily be of use to the traveller and the not too superficial observer of men.
To be sure, widespread and constant peculiarities of head form are less noticeable in America, because of the extreme variability of our population, compounded as it is of all the races of Europe; they seem also to be less fundamental among the American aborigines. But in the Old World the observant traveller may with a little attention often detect the racial affinity of a people by this means.
Two years later, Edward A. Ross sought to apprehend "The Causes of Race Superiority." He saw the differences between the Arab "race" and the Jewish "race" as a central illustration:
It is certain that races differ in their attitude toward past and future. M. Lapie has drawn a contrast between the Arab and the Jew. The Arab remembers; he is mindful of past favors and past injuries. He harbors his vengeance and cherishes his gratitude. He accepts everything on the authority of tradition, loves the ways of his ancestors, forms strong local attachments, and migrates little. The Jew, on the other hand, turns his face toward the future. He is thrifty and always ready for a good stroke of business, will, indeed, join with his worst enemy if it pays. He is calculating, enterprising, migrant and ambitious
You can see more of this here.