President Thomas Jefferson chose William Henry Harrison as the governor of the territory, and Vincennes was established as the future capital.

The land containing Hendricks County was brought into the possession of the United States by the Treaty of St. Mary's in 1818 (known as New Purchase).

[6][7] Until its governing structure was organized, the territory was assigned to neighboring counties for legislative and enforcement matters.

[8] Prior to the New Purchase treaty, the territory of Hendricks County had been occupied by the Dakota tribe, although there were no significant native villages within its future borders.

The treaty authorized the territory to be surveyed by the federal government, with land being available for settlement thereafter.

The town plat was filed for record in October 1824; a court house was erected and in operation there by 1826.

[11] The county's low rolling hills are entirely devoted to agriculture or urban development, except for wooded drainages.

[12] The highest point on the terrain (1,030 feet/310 meters ASL) is a small rise 1.5 miles (2.4 km) WNW from Danville.

The commissioners execute acts legislated by the council, collect revenue, and manage the county government.

In addition, two magistrates appointed by the elected judges serve the county as judicial officers.

There are currently three town courts that also operate in Hendricks County, one each in Avon, Brownsburg, and Plainfield.