In the 19th Century, in New York and other cities, streets were unpaved, muddy, and littered with horse manure. Because of this, an important fixture in front of many houses was a boot scraper.
Usually, the scraper was part of the design of the railing- you wouldn't know it was there if you werent looking for it. The red arrow below is pointing to the scraper part.
All of these pictures were taken in the West Village. Chelsea is another good boot scraper-sighting neighborhood.
