 Harrison County was originally part of Knox County and Clark County but was separated in 1808 . It was the first Indiana county formed by the Indiana territorial legislature and not the Governor . The county originally contained land that is now parts of Crawford , Floyd , Washington , Jackson , Clark , Lawrence , Perry , Scott and Orange Counties . The county was named for William Henry Harrison , the first governor of Indiana Territory , and later a General in War of 1812 , hero of Tippecanoe , and the 9th U.S. President . Harrison was the largest land holder in the county at the time and had a small estate at Harrison Spring . 
