 ross county is a county located in the appalachian region of the u.s. state of ohio. according to the 2010 census, it has a population of 78,064, which is an increase of 6.4% from 73,345 in 2000. its county seat is chillicothe, the first and third capital of ohio. established on august 20, 1798, the county is named for federalist senator james ross of pennsylvania.  ross county comprises the chillicothe, oh micropolitan statistical area, which is also included in the columbus-marion-zanesville, oh combined statistical area. ==history== as of 1848, ross county was described as having almost "one hundred enclosures of various sizes, and five hundred mounds," as well as numerous tumuli created by indigenous peoples of the americas by ephraim george squier and edwin hamilton davis in their book, ancient monuments of the mississippi valley. they describe the earthworks as ranging from five to 30 feet in size, and enclosures of one to 50 acres large. ==geography== [[image:ohio state route 180.jpg|thumb|right|290px|countryside northeast of chil
1798_establishments_in_the_United_States Columbus,_Ohio_metropolitan_area Counties_of_Appalachia Ohio_counties Populated_places_established_in_1798 Ross_County,_Ohio