J. Stryker personal handstamp
Postal clerks who distributed mail were required to have a 'personal postmark' device that showed their name, work assignment location, train/trip/tour (abbreviated "TR") number, and date. Imprints were made upon facing slips, pouch/sack labels, and official correspondence. On occasion, imprints appear on the rear of special delivery or registered mail envelopes, indicating that the clerk performed distribution of that mail piece.
This specimen, marked 'Hoboken, NJ' and 'J. Stryker', was made after the mid-1950s, when the Post Office Department filled requisitions for these devices. Prior to that era clerks procured or made their own personal postmarkers at their own expense.
Hoboken terminal was one of several Postal Transportation Service mail sort station facilities in the New York City metropolitan area. Unworked mail from Railway Post Offices as well as all parcel post was sorted at these locations.