At first, Davenport wished to bar the immigration only of people afflicted by specific disorders — epileptics, the “feebleminded” and others of similarly troublesome (to Davenport) disability. But soon he was caught up in a racialist whirlwind initiated by “The Passing of the Great Race,” a book by Madison Grant, the founder of the Bronx Zoo and the era’s most prominent conservationist. A bilious stew of dubious history, bogus anthropology and completely unfounded genetic theory, Grant’s work persuaded Davenport and others that the American bloodstream was threatened not by suspect individuals, but by entire ethnic groups.

First published in 1916 and reissued in a series of revisions over the next eight years — all of them brought into print by Maxwell Perkins, the celebrated editor of F. Scott Fitzgerald and Ernest Hemingway — “The Passing of the Great Race” savagely denigrated the peoples of eastern and southern Europe while exalting the “Nordics” of northwestern Europe. With the presumed authority of scholarship, he summarized the essential argument of racial eugenics.

“Whether we like to admit it or not,” Grant wrote, “the result of the mixture of two races, in the long run, gives us a race reverting” to the “lower type.” Lower than Nordics were the questionable “Alpines.” Lower than the “Alpines” were the woeful “Mediterraneans.” And, he concluded, “the cross between any of the three European races and a Jew is a Jew.”

Grant was not an actual scientist. But Henry Fairfield Osborn, a world-famous paleontologist and his closest friend, definitely was. Osborn, who once expressed his opposition to the extension of the Westchester Parkway near his country estate because it would bring thousands of “East Side Jews” to the area, presided over the American Museum of Natural History for 25 years, and made that institution the beating heart of the combined eugenics and anti-immigration movement. “I am convinced,” said Osborn, that the “spiritual, physical, moral and intellectual structure” of individuals is “based on racial characteristics.” It wasn’t a matter of ethnic bias, he said — it was “cold-blooded” science.

Other scholars rallied to the cause. Robert M. Yerkes — his name immortalized today at the Yerkes National Primate Research Center in Atlanta — conducted a severely flawed series of tests of American servicemen purporting to establish the intellectual inferiority of eastern and southern Europeans. Charles W. Gould, a lawyer in New York, sponsored “A Study of American Intelligence,” by Carl C. Brigham, a young Princeton psychologist (and later the inventor of the SAT). Brigham’s conclusion: “There can be no doubt that recent history has shown a movement of inferior peoples or inferior representatives of peoples to this country.”

At the same time, Perkins and his colleagues at Charles Scribner’s Sons published a raft of books promoting racialized eugenics. Scribner publicists wrote in one promotion piece: “The inrush of lower races is threatening the very blood of our country.” Perkins’s authors were echoed in the country’s leading magazine, The Saturday Evening Post. “Race character is as fixed a fact as race color,” the Post declared. “Thirty years ago,” the magazine insisted in another article, “science had not perhaps sufficiently advanced to make us fully aware” of the danger of open immigration. Now it had.