Lone Elm was one of America's most historic and important frontier trail camp sites, serving for four decades beginning in 1821 as a campground and rendezvous point for the Santa Fe, Oregon, and California Trails. Thousands of traders traveling to and from Santa Fe, gold seekers rushing west in 1849, Oregon and California emigrants, soldiers, mountain men, and missionaries passed through and spent time there, and visitors included John Fremont, Kit Carson, Francis Parkman, and the ill-fated Donner party of 1846. First known as Round Grove, it was named by the earliest traders to Santa Fe, and by 1827 it shared use with nearby Elm Grove, about 2 miles northwest on the same Cedar Creek, the two places often being mistaken for each other. By the mid-1840s the site had become known as Lone Elm because the original grove had been reduced to a single huge elm tree. Used by traders and emigrants on their first or second night out from Westport or Independence, it also saw frontier military movement during the Mexican War in 1846. Several soldiers who died of cholera were buried there, along with gold seekers who died of the same disease. By the end of the 1840s the old lone elm tree had disappeared after being used for firewood, though false reports of its survival continued into the 1850s. In the post-trail period, Newton Ainsworth became the first owner of the property and developed a successful farm there while strongly advocating for Lone Elm and its location on his farm.