Although Pilot Grove is unincorporated, it has a post office, with the ZIP code of 52648,[3] which opened on May 1, 1837. There has not always been a Pilot Grove post office since that date: it was discontinued on June 30, 1894, and when it was reestablished on August 7, 1895, it was under the name of Overton. The name was not restored to Pilot Grove until March 19, 1908.[4]
Pilot Grove was laid out in 1858.[5] Its population in 1925 was 65.[6] The population was 65 in 1940.[7]