James Sullivan Norris, a New England transplant, was probably the first legal settler in the area; he set up a wheat farm in 1842 in an area he called Cottage Grove. He was soon joined by a handful of other people, also from New England. Those early settlers brought their Greek Revival architecture and so much attitude with them that the area was nicknamed New England of the West. Old Cottage Grove was not on the river but was connected to river towns by wagon roads early on. In 1854 John Furber built an Italianate house that is still standing, as is the house built by Robert and William Watson in 1851. John and Joseph Furber platted the village, now known as Old Cottage Grove, in 1871.
In 1868 there were 68 farms around Cottage Grove totaling 4,000 planted acres that produced a total of 82,000 bushels of crops, 72,000 of which were wheat. Eventually many switched to dairy farms, though, as wheat proved to be unsuitable over the long term. Cottage Grove hosted the first Washington County Fair in 1871, and, from what I’ve learned, that may have been when the village peaked. The area stayed largely rural until the 1960s when new highways fueled rapid suburbanization, and the entire township incorporated as the Village of Cottage Grove (in 1965); in 1960, the village had fewer than 5,000 residents, while it has nearly 35,000 today.