[2] The county was created on March 22, 1820, and was named for Oliver Hazard Perry, a hero of the War of 1812, who had recently died.

[4] Green Park, an unincorporated village located in northeastern Tyrone Township, serves as Perry County's midpoint between the Conococheague Mountain in the west and the Susquehanna River to the east.

The terrain slopes to the northeast,[6] with its highest point on the Blue Mountain Ridge, which delineates the border between Perry and Cumberland counties.

The ridge peaks at 0.83 miles (1.34 km) NE from Perry County's southmost corner; it measures 2,269 ft (692 m) ASL.

[7] Perry County is one of the 423 counties served by the Appalachian Regional Commission,[8] and it is identified as part of the "Midlands" by Colin Woodard in his book American Nations: A History of the Eleven Rival Regional Cultures of North America.

To this day, canoeing and kayaking are forms of recreation which utilize the Shermans Creek and other waters in the county.

Perry County has a hot-summer humid continental climate (Dfa) and average monthly temperatures in New Bloomfield range from 28.5 °F in January to 73.2 °F in July.

Common trees include red maple,[15] Virginia pine, oak, eastern white pine,[16] eastern hemlock,[17] birch, shagbark hickory,[18] and juniper, though American sycamore, ironwood (ex: Hop-hornbeam, American Hornbeam), sugar maple, black walnut, elm, alder, black cherry, black locust, and sassafras are also fairly common.

Ferns also grow along streams and in shaded areas, and are also commonly seen in Perry County woodlands.

The United States Office of Management and Budget[34] has designated Perry County as the Harrisburg-Carlisle, PA Metropolitan Statistical Area (MSA).

In 2016, Donald J. Trump received 73.07% of the presidential vote, compared to 21.67% to Hillary Clinton, and 5.26% for candidates Gary Johnson, write-ins, Jill Stein, and Darrell L. Castle, respectively.

[40] There are numerous historical books written about the county, available at the Council of the Arts in Newport as well as other establishments.

They cover various topics of the county's past, including an historical overview of the Blain area; an account of the life of the early settlers along the Shermans Creek in three townships;[41] and an account of a Civil War battle on Sterrett's Gap.

Under Pennsylvania law, there are four types of incorporated municipalities: cities, boroughs, townships, and, in at most two cases, towns.

[56] Nearly every stream's basin hosted a sawmill, providing wood for early buildings and boardwalks.