The Walnut Grove area was first settled in the 1830s. Families from Tennessee made up many of the early settlers including; Williams, Walsh, Mallory, Leeper, Williamson, Sumners, Carey, Sims, Killingsworth, Bartleson, Welch, Looney. Many of these families still have descendents in the area.
In early days, the site of Walnut Grove was widely known as "Possum Trot"and was first incorporated as Walnut Grove in 1866. Other milestones include: