In the 1850's, the Great Military Road from Fort Leavenworth to Fort Riley, along with the Oregon Trail, passed through Saint Mary's. Military traffic, emigrants traveling West, settlers, and stage coach lines used this route, and Stage station #4 for the Leavenworth and Pike's Peak Express was located in Saint Mary's. In 1850, a war party of Pawnees raided the Indian Settlements near Saint Mary's. South of the river stood Uniontown, a Potawatomi village and trading post that was abandoned in 1859. Two miles east is Bourbonnais Creek, named for Peter Bourbonnais, a French/Potawatomi Indian who operated a toll bridge, circular saw mill, and grist mill.