Jay County is bounded on the north by Adams and Wells Counties, on east by Mercer and Darke Counties, Ohio, and on the south by Randolph County and on the west by Delaware and Blackford Counties. The area of the county is 377 square miles, or 241,692 acres. In 1860 the population was 11,378 and in 1870 14,979.

   Jay County was created by an act of the Indiana General Assembly of February 7, 1835 and organized by a law of January 30, of the following year, effective March 1st. On December 5, 1835, it was ordered by the Board of Commissioners “that the County Seat of Jay County be designated and known by the name of Portland,” – by an act of the Indiana Legislature of January 25, 1843, Portland was incorporated as a town. In 1883, it was incorporated as a city. There are twelve townships in Jay County, namely: Wabash, Bearcreek, Jackson, Penn, Knox, Greene, Wayne, Noble, Madison, Pike, Jefferson and Richland. It was named for John Jay, first Chief Justice of the United States Supreme Court.

   The County was organized by another act passed, and approved January 30, 1837. In 1821, Peter Studabaker (born in Westmoreland County, Pennsylvania, in 1790) settled on the south bank of the Wabash River, at what is now New Corydon, Jay County. Here he built a crude cabin, of small round logs. This was the first dwelling erected in the county. There was no other house within thirty-five miles. The first person born in Jay County was Abram Studabaker, in the little cabin on the Wabash River, September 29, 1822.