Morion’s theory; so did many religious persons, who considered it an attack on Scriptural truth. But it was eagerly seized upon by defenders of slavery who saw in it a “scientific” basis for racial inequality. The battle lines were drawn.

The most prestigious convert to the doctrine of separate creations was Louis Agassiz, who arrived from Switzerland in 1846, already persuaded from fossil studies that all animal species except man had been separately created and confined to the “zoological province” in which they lived. Talks with Morton and his followers helped convince Agassiz that the races, too, were different species. In March of 1850, before a meeting of the Association for the Advancement of American Science at Charleston, South Carolina, he declared that the races were “well marked and distinct” and did not originate “from a common center … nor from a common pair.”

Special creationists were jubilant: ”… with Agassiz in the war,” wrote one, “the battle is ours.” Their opponents were stunned. Agassiz was accused of unorthodoxy and was attacked for advocating slavery. Such assaults bewildered him; Agassiz was, in fact, deeply religious and largely indifferent to politics. Scientists, he believed, had a duty to search for truth wherever it led them, regardless of political and social consequences.

His method was to “study nature, not books,” and after the Charleston meeting he traveled to Columbia to conduct field research on race. His host was Dr. Robert W. Gibbes, an admirer of Morton. Together, Gibbes and his illustrious guest traveled to nearby plantations where, Gibbes wrote, “Agassiz was delighted with his examinations of Ebo, Foulah, Gullah, Guinea, Coromantee, Mandrigo and Congo Negroes,” and found enough evidence to “satisfy him they have differences from other races.” Agassiz concentrated exclusively on African-born slaves and their first-generation offspring. By means of this restricted sample he hoped both to define the anatomical variations unique to “the African race” in its original form and to establish a standard against which to measure the permanence of racial characteristics among American-born slaves of more remote African ancestry who had been exposed to a temperate climate for several generations. (African-born slaves in fact constituted only a tiny fraction of the U.S. slave population in 1850, more than four decades after Congress declared the importation of slaves illegal; some of those whom Agassiz examined must have been smuggled into America as part of the illicit trade that continued until the Civil War.)

His firsthand studies completed, Agassiz departed from Columbia at the end of March, but he evidently left instructions for Gibbes to gather corroborative photographic evidence — one of the first such instances in scientific history. Gibbes enthusiastically complied, arranging for J. T. Zealy to photograph the slaves Agassiz had examined, then posing each one nude to point up anatomical details in which

the scientist had shown special interest and, finally, labeling each image with the subject’s first name, tribe, and owner.

Gibbes was pleased with his work. “I have just finished the daguerreotypes for Agassiz of native Africans of various tribes,” he wrote to Morton in June. “I wish you could see them.”

Agassiz was probably satisfied as well; certainly his Columbia visit had reinforced his belief that Africans were a distinct species.

Although Agassiz never wavered in his belief, the theory of special creations was soon to be supplanted by the theory of evolution propounded by Charles Darwin in his Origin of Species (1859). Modern anthropologists, of course, are unanimous in their belief that mankind is a single species.

Agassiz’ theory was discredited by the mid-1860’s, but the daguerreotypes survived; and it is ironic that these pictures, made to demonstrate the supposed inferiority of their subjects, instead conferred a kind of immortality on the men and women we know only as Renty and Delia, Jem and Jack.

It was no consolation for the humiliation they endured both as slaves and as objects of scientific curiosity, but a rare gain for those who now encounter these people as memorably real survivors of a painful epoch.