Potawatomi, Ottawa, and Ojibwe (Chippewa) Native American tribes inhabited the Des Plaines River Valley prior to Europeans' arrival. When French explorers and missionaries arrived in the 1600s in what was then the Illinois Country of New France, they named the waterway La Rivière des Plaines (English translation: "River of the Plane Tree") as they felt that trees on the river resembled the European plane trees. The first white settlers came from the eastern United States in 1833, after the Treaty of Chicago, followed by many German immigrants during the 1840s and '50s. In the 1850s, the land in this area was purchased by the Illinois and Wisconsin Land Company along a railroad line planned between Chicago and Janesville, Wisconsin. In 1852, the developers built a steam-powered mill next to the river to cut local trees into railroad ties. Socrates Rand then bought the mill and converted it into a grist mill, which attracted local farmers. The Illinois and Wisconsin Railroad made its first stop in the area in the fall of 1854.