William and Charles Bent and Ceran St. Vrain built Bent's Old Fort on the Arkansas River in 1833, where mutual respect, intermarriage, and economic interdependence with Plains Tribes allowed peaceful trade, primarily with the Southern Cheyenne and Arapaho for buffalo robes. The fort became the center of a trading empire that included other forts and company stores in Taos and Santa Fe, and during the war with Mexico in 1846 it served as a staging area for the United States' Army of the West, before disasters and disease led to its abandonment in 1849. William Bent, who had known Big Timbers earlier and built cabins and a corral there in the 1840s, established a new trading fort on the cliffs above the Arkansas River in 1853. When the US Army set up there in 1860, the site became the commissary for a military fort tied to the worsening relationship between Plains Tribes and the federal government, and troops marched from there in 1864 to carry out the Sand Creek massacre, in which about 200 Cheyenne and Arapaho people died. In 1905, John Squire Semmens, a Yorkshire-born portrait artist who had moved to Kansas City, gained American citizenship in 1887, brought over his wife Alma and sons William, Archie, and Edgar, later settled in Colorado, and bought the 4.44-acre Bent's New Fort parcel with a $5.00 down payment as part of his effort to raise bees and trade honey. His purchase became a lasting family legacy, and great-grandsons Brad Semmens and Gary McCall later expanded that legacy by buying surrounding land and protecting the site as an archeological preserve.