Middletown is a town in Frederick County, Maryland, United States. The population was 2,668 at the 2000 census. Middletown is a small, rural community steeped in American history. Located in the beautiful Middletown Valley that stretches between the Catoctin Mountains on the east and South Mountain on the west, the town reportedly gained its name from its location midway between those ranges.
A young Lieutenant George Washington, while surveying the South Mountain area, reported that the valley to the east was one of the most beautiful places he had ever seen. Later, as a Colonel in 1755, he was to accompany General Braddock on the old Indian Trail that ran through the valley on his way to Fort Cumberland.
The early German and English settlers started to arrive in the valley in the 1730s. Among them was Michael Jesserong, who paid £66 for 50 acres (200,000 m2). He named his property Middletown and sold the first lots there in 1767, the date officially marked as that of the town’s founding.