2 things here.
You are not specifying Latitude/Longitude values for the setView method, which are required. Lat has a range of -90 to 90, and Long -180 to 180.
A zoom level of 3 encompasses an area far larger than New York, so large that it is quite possible you wouldn't be able to see overlayed borders of the US states let alone the roads within a particular city. This then results in a blank canvas because what you are viewing is too small in scale to be seen on the map at the zoom level you are using.
Try replacing your line of code var map = L.map('map').setView([988008, 213104], 3); with this:
var map = L.map('map').setView([40.715646, -73.99933], 14);
Use the zoom control if you need to, but you should now be able to see your layer.