The village of Chestnut Hill was part of the German Township laid out by Francis Daniel Pastorius and came to include the settlements originally known as Sommerhausen and Crefeld, as well as part of Cresheim. It served as a gateway between Philadelphia and the nearby farmlands. During the American Revolutionary War era (late 18th century), the area was one of many summer vacation spots due to its higher elevation, 400–500 feet above sea level, and cooler temperatures than the historic Center City. Chestnut Hill is still stereotypically known as one of the more affluent sections of Philadelphia.
Chestnut Hill became part of the City of Philadelphia in 1854 as part of the Act of Consolidation, when the County and the City became completely coterminous. In the same year, the Chestnut Hill Railroad opened, making an easy commute to and from Center City.
From the mid-19th century through the mid-20th, the neighborhood served as both a 'railroad suburb' and a 'streetcar suburb' of Center City; although it was part of Philadelphia, it was a leafy outlying part functioning as a bedroom community. (It still serves this function, although the streetcars are gone.)
The neighborhood contains a wide variety of 19th and early 20th century residential buildings by many of the most prominent Philadelphia architects. - Courtesy www.wikipedia.org