Connection in pic #2 identifies this as a Canton product, missing the little cover plate that would have the builders name on it.
Nice find! And a pin-connected bridge as well!
I'm pretty sure this is a Canton Bridge Co. product. The hip joint has a missing piece covering the connection between the endpost and upper chord meet, and 2 nuts where the cover was formerly mounted are visible.
http://bridgehunter.com/photos/37/71/377120-L.jpg
This is identical to what I found on a 1901 Canton bridge over in Essex County (with the plate intact):
...In other words, if I had read Michael Q's post first I would have just concurred with him! ;-)