Old map of Bent's Old Fort, established by 4 brothers named Bent and partner Ceran St. Vrain in 1826, five years after Cinco de Mayo of 1821 when Mexico won it's independence from Spain.

The Santa Fe Trail trade route was opened in 1821 and the Bent's trading post was then located between Pueblo and Canon City. The Cheyenne chief, Yellow Wolf, suggested a trading post closer to the Bison herds would make trading easier, so the Bents built on the present site of Bent's Fort between 1828 and 1832.

During the war with Mexico over the influx of European immigrants into the area, the fort was a crucial garrison of the Army. After the war, in 1848, it became a trading post again, but the even greater influx of European settlers and the trading with the Native Americans, spread diseases the indeginous peoples, who had no immunity from and medicine for them, so the local population was devastated.