Wedded to the wilderness, he lost his marriage, his health and his money before dying alone and bank- rupt, himself the epitome of a lone romantic. Lone romanticism, of course, is a western construct – Indian societies are largely based on communality rather than individuality.Curtis belongs to a tradition that originated in Victorian England, known as Pictorialism, which claimed photography was more than a science Representation was not about a real but an ideal world. There is probably no subject that cannot be beautified.” Edward S Curtis, probably the best-known photographer of Indians, perpetuated the stereotype of the Indian brave – courageous in battle, dignified in frequent defeat. The ignorance that Curtis permitted himself of Indian customs and languages was accompanied by the routine elevation of the unknown as the mysterious.Yet Curtis – 60 of whose photogravures are on show at the Barbican, with a separate exhibition of his work at the Atlas Studio Gallery – would claim to have been a devoted lover of “the Indian”, a creature he viewed as mythical as the centaur, and which he exalted in imagery reiterating the skilled union of horse and rider, man and nature.

On the one hand, they were perceived as synchronistic with nature, but, on the other, they were still the “dirty injun”. Photography’s task to “capture eternity in an instant” was continuously sabotaged by its desire to idealise.In On Photography Susan Sontag wrote: “To photograph is to confer importance. Aesthetic exploration accompanied the “exploration” of a land seemingly and seamlessly without frontiers, until the West was won. While victory destroyed the basis of this assumed freedom, the Indians were left as guardians of its mythic status. But there was always another version of the Indian, celebrated in such ballads as Longfellow’s “Song of Hiawatha”, in which “the noble Hiawatha” went off into the sunset after a long and glorious life as “the Beloved”: a romantic fantasy woven around a misappropriation of the “two-legged, four-legged and winged” friends of Indian tales and ancient rock-paintings.For many pioneer writers and artists, being in the New World was also to be at one with the timeless worlds of the free-spirited. Carlisle School and the Fort Marion prison are as much a testament to this as the Sioux massacre by US forces at Wounded Knee in 1890, or the Trail of Tears (the forced marches of the 1830s in which the Cherokees lost a quarter of their nation). This permitted travelling photographers to supply their subjects with invented names, or with costumes displaying tags from the Smithsonian Institute collection.Long before John Wayne rode through a swathe of “redskin” corpses to prove that “the only good Indian is a dead Indian”, there was the the political injunction to “kill the Indian to save the man”.

In the week Abraham Lincoln signed his Proclamation of Emancipation, there was the largest judicial execution in US history, of 38 Dakota men who had participated in the 1862 Sioux Revolt.Then there is the mission boarding school in Carlisle, Pennsylvania, where only four months separate group shots of the same children: they arrive from 16 distinct cultures, but soon merge together, uniformed from their clipped fringes to their shod feet. There’s sadness that no attempt was made to transliterate their indigenous names (they were given new ones). But little is as sad as the incongruous setting at Fort Marion, where native prisoners are photographed in pyjamas, like concentration camp inmates. They are unnamed, but a caption reads “Tropical Scenery – Views by the Florida Club”.What is so striking about this early work of objectifying, categorising and ultimately iconising native Americans is how wrong it was.

That the basis of their treatment was politically and morally wrong goes without saying, but it was also wrong in the new documentarists’ own terms. The notion that science was objective, and that the new disciplines of anthropology and photography were scientifically sound, are belied by their practitioners’ inability to believe what they saw. The most salient factor in this exhibition, which includes books, early film footage and case-notes, is that believing is seeing. Whites, who would have been astounded by the idea that Europe was a homogeneous whole, that Greeks and Greenlanders might have anything much in common, repeatedly failed to recognise the diversity in what are now the 556 registered Amerindian nations (with another 200 still seeking recognition). Here, captioned beneath silhouetted figures, we have “Chiefs of the Desert” and “Ghost Dancers” (who were, in fact, invoking a spirit of renewal in future generations).But no misnomers can disguise the shocking reality of these photographs. Indeed, it is the disguises themselves which compose that reality. A twin portrait from the Hamilton and Kodylek studio in 1880 shows two versions of the same woman, seated against the same outdoor backdrop: first, a bare-breasted Eve staring provocatively; then, a demure Madonna, clothed in a European blouse, eyes downcast.