The overall value of farms and rural land for sale in Indiana's Union County recently on Land.com was almost $4 million. This represents almost 1,000 acres of land and rural real estate for sale in Union County. Union County ranks 91st out of 92 counties in the state for the total acreage of land currently advertised for sale. Of all land and rural real estate for sale in Union County, Liberty had the most land for sale. Union County is the 90th largest county (165 square miles) in Indiana. It's located in the East Indiana region of the state.