In 1787, the fledgling United States defined the Northwest Territory, which included the area of present-day Indiana.

Starting in 1794, Native American titles to Indiana lands were extinguished by usurpation, purchase, or war and treaty.

On November 1, 1814, portions of Warrick and Gibson were partitioned to create Perry County.

Two years later, the northern portions of Gibson and Perry were sufficiently populated to warrant a separate governing structure, so on December 21, 1816 − ten days after being admitted to the Federal Union as a state − the Indiana state legislature authorized the creation of Pike County, taking areas from Gibson, Knox, and Perry counties.

The first commissioners filed a report dated February 15, 1817, naming Petersburg as the seat of government;[7] the city was laid out and platted that same year.

He was killed as a brigadier general during the War of 1812 after his men had captured York (now Toronto), Canada.

[9] The first courthouse in Pike County was a two-story log building, laid on the east side of the Petersburg public square in 1817.

[6] From 1959 to 1963 Vance Hartke and Homer E. Capehart were the U.S. senators for Indiana, both from Pike County.

In 2015, northern Pike County's economy received a boost from the completion of Interstate 69.

The low hills of Pike County have been cleared, leveled, and put to agricultural use, although its many drainages are still wooded.

[10] The highest point on the terrain (650 feet; 200 meters ASL) is the sharp crest of a ridge 2.9 miles (4.7 km) NE of Stendal.

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

The judge of the Circuit Court is elected to a term of six years and must be a member in good standing of the Indiana Bar.