Several years ago, I ran across a snippet of an 1868 response to a letter to a local Pittsburgh newspaper. Intrigued by the description "rookery of shanties up a stinking hollow", and the rebuttal of the residences being "neat, handsome and elegant," I wondered where it was located.
Found it. First part of old Allegheny City, it's now part of northern Pittsburgh.
Gathering information on Pleasant Valley hasn't been easy. One online source says it was originally known as Snyder's Hollow. An 1870 painting of Snyder's Hollow by the American landscape artist Jasper Holman Lawman is part of the Carnegie Museum of Art. The painting looks rural with a couple of houses shown. I don't think I would call them shanties, but I also wouldn't call them elegant.
The best information found on Pleasant Valley is detailed by the Charles Street Rowhouse Historic District which was listed on the National Register of Historic Places in 1984. According to the writeup, Pleasant Valley was named so by the developers who were building spec housing. It was mainly used for rental housing and was part of the development of the Pleasant Valley Street Railway which had horse drawn street cars.
More information on the later development of the area along with changing from horse drawn streetcars to electric streetcars in Pleasant Valley can be read in the book by David Ford Henry.
Ahhh, genealogy. During its lifespan, perhaps both descriptions were correct at one time or another.
Painting of Snyder's Hollow, 1870, by Jasper Holman Lawman
Wikipedia on Perry South (Pittsburgh)
Henry, David Ford, The Genealogy of the Henry Family, 1919.