An illustration from Expedition to Oregon, 1849. Courtesy Oreg. Hist. Soc. Research Library, OrHi84282 (Courtesy Oreg. Hist. Soc. Research Library, OrHi84282)

The federal government transformed some fur trading posts into military forts to protect wagon trains, despite the low occurrence of conflict with Native Americans. Fort Laramie was one of those military posts. Courtesy Oreg. Hist. Soc. Research Library, OrHi85429 (Courtesy Oreg. Hist. Soc. Research Library, OrHi85429)

Illustration of Oregon Trail wagon train, by unknown artist (Courtesy Oreg. Hist. Soc. Research Library, 58569)

From Oregon's Golden Years, by A. Burr. Courtesy Oreg. Hist. Soc. Research Library, OrHi86985 (Courtesy Oreg. Hist. Soc. Research Library, OrHi86985)

Sketch by J.H. Beadle of a wagon train crossing a river. Courtesy Oreg. Hist. Soc. Research Library, OrHi88286 (Courtesy Oreg. Hist. Soc. Research Library, OrHi88286)

Illustration depicting the Native Americans pioneers encountered along the trail. Scott's Bluffs is in Nebraska. Artist was George H. Baker, and his drawings appeared in Crossing the Plains, by J.M. Hutchings. Courtesy Oreg. Hist. Soc. Research Library, OrHi98912 (Courtesy Oreg. Hist. Soc. Research Library, OrHi98912)