It is believed that the origin of Baden lies in its location on the principal road between St. Louis and the 18th Century Spanish Fort Don Carlos Tercero Del Rey at the mouth of the Missouri River. This fort was built in 1768 by Captain Rios, who was sent north with 25 soldiers to establish authority and to ward off hostile bands of Indians. Rios named the fort after the heir to the Spanish throne. In 1806, this fort was superseded by Fort Bellefontaine, which was founded on higher ground by General James Wilkinson, the American governor of the newly purchased Louisiana Territory. Bellefontaine was the French name of a large spring at the foot of the bluff where the fort was erected. The fort was occupied until 1827 when the troops were moved to Jefferson Barracks.

Image - Hall Street North Broadway area in 1875