| pop_est_as_of =
| pop_est_footnotes =
| population_est =
| name =
Middletown is a borough in Dauphin County, Pennsylvania, on the Susquehanna River, southeast of Harrisburg. As of the 2020 census, it had a population of 9,550. It is part of the Harrisburg–Carlisle Metropolitan Statistical Area.
History
18th century
Middletown was founded in 1755 along the left bank of the Susquehanna River and was incorporated as a borough in 1828 after a sudden boom in development and population occurred as a result of the construction of the Union Canal, connecting Lancaster to Middletown. In 1824, Pennsylvania's state legislature authorized and funded the canal construction as part of the broad sweeping commercial initiative called the Main Line of Public Works; a forward looking project designing to connect Philadelphia to Pittsburgh by canals and river navigations and Philadelphia to challenge New York City and the Erie Canal for emerging mid-western markets beyond the Allegheny Mountains.
Middletown was selected as the western terminus of the Union Canal, and it was named from its location halfway between Lancaster and Carlisle, where an ascent exists to a low pass allowing easier wagon-era travel among the barrier mountains of the Ridge-and-valley Appalachians giving access into north-central Maryland and the valley of the Potomac River. It is the oldest incorporated community in Dauphin County and is located within a rich agricultural area forming the western edge of Pennsylvania Dutch Country.
19th century
The George Everhart (Frey) Trust, named for a citizen of Middletown from the 1800s, still manages leases on much of the land in and around Middletown. The trust was founded to operate the Frey Orphanage and did so for many years, in three locations in Middletown. The orphanage eventually closed, and the final location, on Red Hill, has become the , a Diakon Lutheran senior living facility.
20th century
thumb|left|Photo from 1979
Middletown is located 3 miles (5 km) north of the Three Mile Island Nuclear Power Plant. The Unit #2 reactor at the Three Mile Island Nuclear Power Plant suffered a partial meltdown in 1979, causing then Pennsylvania governor Dick Thornburgh to order the evacuation of pregnant women and pre-school children from the area. Within days, 140,000 people had left the area. President Jimmy Carter visited Middletown's Community Building to calm the nerves of anxious residents.
Because the town is old, diverse historic architectural styles abound. Middletown has everything from log houses, some whose construction is obscured by modern siding, to Victorian mansions, and beyond. The Simon Cameron House and Bank, B'nai Jacob Synagogue, St. Peter's Kierch, Charles and Joseph Raymond Houses, Henry Smith Farm, and Swatara Ferry House are listed on the National Register of Historic Places.
Geography
Middletown is located in southern Dauphin County at (40.198491, -76.729326). Its southern border is along the Susquehanna River, and its eastern border is formed by Swatara Creek, across which is the borough of Royalton. Pennsylvania Route 230 (Main Street) leads northwest to the center of Harrisburg and southeast to Elizabethtown. Via the PA 283 expressway it is southeast to Lancaster. The Pennsylvania Turnpike (Interstate 76) passes through the northern part of the borough, but the nearest access is west near Highspire. The town has Amtrak Keystone Service at Middletown station.
According to the U.S. Census Bureau, the borough has a total area of , of which is land and , or 2.33%, is water.
Demographics
As of the census