The value of all farms, hunting land and other rural land and acreage for sale in Union County, Indiana, recently was almost $5 million, representing a combined 198 acres of land for sale in Union County. Union County ranks 92nd in Indiana for the total number of acres of land currently advertised for sale. Liberty featured the most land for sale. Union County is Indiana's 90th largest county (165 square miles). It's located in the East Indiana region of the state.