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 is so far away for NYC 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 will make the canvas look blank.
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.