[3] The Indiana State Legislature passed an omnibus county bill on February 7, 1835[4] that authorized the creation of thirteen counties[5] in northeast Indiana, including Jay - the only county in the United States named for John Jay, co-author of The Federalist Papers, Secretary of Foreign Affairs under the Articles of Confederation, and first Chief Justice of the United States.

Its low, rolling terrain is entirely devoted to agriculture or urban development.

[7] Its highest point (1,121 feet/342 meters ASL) is a small rise on the east border with Ohio, 2,600 feet north of the county's SE corner.

Representatives, elected to four-year terms from county districts, are responsible for setting salaries, the annual budget, and special spending.

The commissioners execute the acts legislated by the council, collecting revenue, and managing the day-to-day functions of the county government.

[14] County Officials: The county has other elected offices, including prosecuting attorney, assessor, sheriff, coroner, auditor, treasurer, recorder, surveyor, and circuit court clerk Each officer is elected to four-year terms.

[16] As of the 2010 United States Census, there were 21,253 people, 8,133 households, and 5,647 families in the county.

The reference is to the unincorporated town of Fiat near the intersection of Indiana State Routes 1 and 18 in Jay County.