In this context, the word "Dutch" does not refer to the Dutch people or their descendants. "Dutch" in this case is likely left over from an archaic sense of the English word "Dutch", compare German Deutsch ('German'), Dutch Duits ('German'), Diets ('Dutch'), which once referred to any people speaking a non-peripheral continental West Germanic language on the European mainland. Alternatively, some sources give the origin of "Dutch" in this case as a corruption or a "folk-rendering" of the Pennsylvania German endonym "Deitsch".
Speakers of the language are primarily found today in Ontario in Canada and in Pennsylvania, Ohio, and Indiana in the United States. Historically, the dialect was also spoken in several other regions where its use has either largely or entirely faded. The use of Pennsylvania German as a street language in urban areas of Pennsylvania (such as Allentown, Reading, Lancaster and York) was declining by the arrival of the 20th century, while in more rural areas it continued in widespread use through the World War II era. Since that time, its use has greatly declined. The exception to this decline is in the context of the Old Order Amish and Old Order Mennonite communities, and presently the members of these two groups make up the majority of Pennsylvania German speakers. (see Survival below).
Some other North and South American Mennonites of Dutch and Prussian origin speak what is actually a Low German dialect, referred to as Plautdietsch, which is quite different from Pennsylvania German.