In 1886 William T. Hornaday, the Chief Taxidermist of the US National Museum, led the "Smithsonian Institution Buffalo Outfit" to Montana. The American bison was fast heading toward extinction and the mission of the expedition was to locate those of the elusive animals that remained and obtain specimens for the scientific collection at the museum. The successful expedition produced the most complete scientific series, and the finest artistic grouping of taxidermied specimens of the American bison anywhere in the world. Haunted by the scattered skeletal remains of the millions of slaughtered bison that peppered the Eastern Montana Plains, Hornaday fought to establish the National Zoological Park, which would provide sanctuary for bison and other endangered species, and a captive breeding program, which would result in the eventual reintroduction of the American bison to the wild.