What Year Is This Stamp

Good morning - Can anyone tell me what Scott number this stamp. I'm mostly curious about the history. Thank you!

The stamp looks to me like a Scott 405 from 1912. Because it has no perforations on the bottom and right 2 sides, the stamp is likely from a booklet pane of 6 stamps (405b) which is common for travelers to use while on trains -- the "TR.3" in the cancellation indicates this is an RPO cancel (Railway Post Office), so the postcard was mailed from a train, "Trip #3". I cannot make out the cancellation but the image on the other side of the postcard may give a clue of the origin.

There are many variations of this stamp depending on the type of watermark and perforations. You can find an identifier here,
https://stampsmarter.org/1847usa/wa...d31perf.html

Thank you for responding! The pic on the back is the College of Law at the University of Illinois.

It is Feb 1, 1914. The message starts 2-1-14