"...the average Harlemite is in a continuous swim of development..."  A phrase that seems to sum up the experience of many residents over the last decade.

Yet the quote is from 1890 when the first building boom transformed Harlem from a sleepy backwater to residential suburb of The City:

The Harlem Jets and the 3 Avenue Trolley

The playing field where the Harlem Jets play at 129/128th streets and 3rd/2nd Avenues, 

was once a major transportation terminus where streetcars and Els either turned around to head back down into Manhattan, or continue up into the Bronx.

Ebay had this image of 129/3rd Avenue from 1940 of transportation and buildings that are long gone:

For the listing see:

https://www.ebay.com/itm/274302242324?ul_noapp=true