Hardin County is the product of millions of years of history. Most basic is the soil which is the result of the transformation of the surface rock. This rock was of a limestone nature. The coming and going of vast inland seas disintegrated the surface of the rocks in ages between the marine invasions. Further erosion and mixture of soils were brought about by the coming and going of glaciers. An ideal soil mixture was created which became the base for a thick growth of forest and grasses.

Hardin County was in a flat area where waters drained slowly in many directions. The Scioto and Great Miami Rivers in the southwestern part of the county and the Blanchard and Ottawa Rivers in the northern part eventually joined the Maumee River outlet to Lake Erie. This meant a need for artificial drainage which came about through state authorizations-a county and township system of public drainage which cleared thousands of acres of land.

The forest-dwelling Wyandot and Shawnee Indians were the first inhabitants of this territory. The Indians were supported by the French who wanted their fur trade, until the English conquest of French Canada in 1756-63. The English then encouraged the Indians to remain in their Ohio hunting grounds. The War of 1812 ended all hope of Anglo-Indian control of Northwestern Ohio. In 1817, the Hardin County area was formally given up when the last Indian Village was abandoned.

White settlement of this territory began in about 1830. by 1833 Hardin County was created (named in honor of Colonel H. Hardin who had been killed in 1792 during the Indian Wars) and the village of Kenton was laid out. Livestock raising was a main source of income for many years and highly fertile muck soil let to the production of great quantities of onions, potatoes, sugar beets, corn and other truck crops.

The modern drainage of the county has increased the value of land and agricultural production which has led to great scientific improvements in feed production. the use of artificial insemination has greatly increased the quality of breeds and milk production. Hard surfaced roads, trucking and refrigeration facilities have enabled the dairy farmers to deliver their milk to a greater number of outlets.

Hardin County is still about 75% rural with a large urban element in such communities as Kenton and Ada. Kenton, county seat of Hardin County, is a vigorous trading and manufacturing city whose population is estimated to be about 8,336. Ada is famous for its Ohio Northern University founded in 1871 by Henry S. Lehr.

The population of Hardin County is 31,945. Hardin County has a land area of 467 square miles which is comprised of 298,880 acres. The average elevation is 980 feet, above sea level.

Hardin County is the home of Jacob Parrott who received the 1st Congressional Medal of Honor.