White settlers began moving into what would later become McLean County in the 1820’s. Townships existed pursuant to the Northwest Ordinance adopted by the Continental Congress, but the townships were not identified by name until 1858.
The early settlers described where they were living in terms of the nearby grove of trees. Early settlers in northwest McLean County settled near the groves because of readily available fuel and building material, and because cast-iron plows would not scour in the heavy prairie sod. Travel between the groves were along abandoned Indian trails, (many of which continue to be used today).
White Oak Grove was one of the larger groves. It stretched for about twelve miles east to west, along both sides of the Mackinaw River, and was about eight miles wide from the north to the south. Today this grove lies almost entirely in Woodford County. Upriver toward the east was referred to as “East White Oak”. Downriver to the west was often referred to as “Lower Oak Grove”. Early settlers in the area often referred to their location as “White Oak”, or “The Grove”, or “Oak Grove”.
Prior to the civil War, when early settlers referred to “White Oak”, they were likely referring to the general area of the very large White Oak Grove, rather than to the Village of Oak Grove or the small White Oak Township in McLean County.