While noodling about one day, I stumbled across Virtual Harlem, a reimagining of New York City's Harlem neighborhood in the 1920s and 30s.
Harlem (originally Nieuw Haarlem, after the Dutch town of the same name) runs from 110th to 155th Streets the width of Manhatten, from the East River to the Hudson River. East of Central Park, the area down to 96th Street is also considered part of Harlem (now Spanish Harlem). The area was settled by the Dutch in the mid-17th century and was taken by the English in 1664. For many decades the area was mainly farmland, with rich soil supporting large plantations. The population of Manhattan was largely confined to the southern part of the island, and connections between the population and Harlem were poor.
In the mid-19th century, as the land became depleted, Harlem's fortunes declined. The elevated rail line was extended to Harlem in the 1880s, which helped revive the area. After several boom and bust cycles in the housing market, blacks started moving into the area in large numbers in the early part of the 20th century, bolstered by the large black migration out of the South. In time, Harlem became the center of black culture in New York City, famous for entertainment venues such as the Cotton Club and the Apollo Theater.
Virtual Harlem has its version of the Cotton Club, which featured the leading black entertainers of the time, such as Duke Ellington, Count Basie, and Cab Calloway (though famously denying entry to black patrons).
The Apollo Theater was where Ella Fitzgerald got her start, and featured other black performers. The theater also featured vaudeville acts.
The Virtual Harlem build has a number of fine brownstone buildings, such as the fire house - now an art museum - depicted below...
...as well as the library (which contains reference materials about the area).
I'm no expert on what the area looks like today, much less in the first half of the 20th century, but the build seems to lack a certain cohesiveness. Sidewalks and streets give way to grassy areas that seem out of place. Rather than seeing a section of a city, it appears more of a collection of buildings. And, unfortunately, like so much of the grid, it was nearly entirely deserted during my visits.