1766-1813 1785-1851 1849-1938 1860-1890 19th-century alexander american-west americanbison audubon biography birds buffalo conservation cultural-conflict descriptionandtravel environmentalism frontier frontiersman great-plains grinnell history historynationalaudubonsociety indigenous-peoples johnjames native-americans natural-resources naturalist ornithologists plains-indians preservation ranching unitedstates westward-expansion wildlife wildlife-preservation wilson