The name
Knox Grove is derived from William Knox, who first settled the area around 1830. By 1846, Knox Grove was a settlement of roughly 14 families covering an area of . The following year, the first
schoolhouse was started out of the (now abandoned) home of Mr. Knox. In 1848, an
American black bear weighing was reported as being killed by a group of men in the northern reach of the grove. That same year, a
post office opened under the name of Ovid. By 1855, the
Illinois Central Railroad's choice of routing led to the creation of the nearby town of
Sublette, where the majority of the population of Knox Grove shortly relocated. ==Ecology==