Plat maps are maps of land ownership.  Each farm is delineated on a township basis.  Plat maps for most counties are available since 1900 and some counties have maps as early as the 1870’s.  The succession of plat maps allows landowners to visually identify changes of land ownership.  Most of the time, the farm has changed shape since the first purchase. 

The links below provide images of plat maps of Pilot Grove (located in the southwest corner of section 24) over a period of nearly half a century.