The Photographic History Collection at the National Museum of American History holds an extraordinary series of early color photographs: sixty-two color daguerreotype plates made by Rev. Levi L. Hill in the early 1850s in Westkill, Greene County, New York. This is the world's largest collection of Heliochromy, a rare early color photographic process based on silver chloride.
Hill’s color process was extremely complex, consisting of coating a daguerreotype plate with multiple layers of a compound of different metals that reacted to the different colors in the spectrum. The achievement of inventing a color photographic process in 1850 was even more remarkable considering that Hill was not trained as a scientist and lived in a very remote area of New York State.
Yet Hill was undisputably an important figure in the early history of American photography, an entrepreneur and an enthusiastic innovator. He wrote the first, and one of the best, manuals on daguerreotypy, "A Treatise on Daguerreotype" in 1850; and in 1856 he wrote the first manual on color photography, "Treatise on Heliochromy", which includes a description of his experiments and an overview of all the means of chemically producing pictures in natural colors with light.
Among important works by Hill are many daguerreotype photographs of European color prints, and art reproductions such as this Hillotype copying a print of a man fallen from his horse. X-ray analysis of this plate shows iron and bismuth pigments hand applied to the plate in the brown saddle area after production.