- These commemoratives were the first to be issued at the request of special groups.
- These commemoratives were the first to be issued as single commemoratives (not as a set of 1 cent, 2 cent, 5 cent, etc.).
- They were the first commemoratives issued in imperforate form, and, except for the 611 Harding issue, the only US commemoratives issued in full sheet imperforate form.
- 368V and 368H are the first US commemorative coil stamps (but the USPO didn't perforate them, they were for the private perforators).
- They are among some of the later issues to be printed on the flat press, and can be found in a variety of spacings between stamps (2 mm and 3 mm).
- The imperforate issues (368, 371, 373) are valued about as much in used condition as in mint and sometimes more than mint.
- The circulation figures for 368 are similar to the 15 cent Columbian.
- The circulation figures for 369 & 371 are similar to the 30 cent Columbian.
- The circulation figures for 373 are comparable to the 50 cent Columbian.
- It's possible that half or more of each of the imperforate issues were used in private vending machines.
- They are the only US commemorative issues that can be found in a large variety of private perforations (Schermack, Brinkerhoff, Farwell, Mail-o-meter [Mail-om-eter], US Auto Vending, and others), and these private perforations are undervalued in comparison to their rarity (note: a few of the Farley commemoratives can occasionally be found with private perforations).
- Very few pre-printed stamp collection albums even show spaces for the imperfs and private perforations; consequently, few collectors are even aware of their existence.
- 369 was the only US commemorative issued on experimental blue paper (all of the others on blue paper were Washington/Franklin regular issues, #357, 358, 359, 362 and 364).
- The only perfins on the imperforate issues are Werner.
- They are still relatively inexpensive (except for 369 and of course the rarest private vending perforations), yet challenging to find.
- The 100th anniversary of these stamps is approaching (the year 2009).
- The 2-cent Lincoln is among a very small handful of US issues that have "star" plates (used to indicate experimental 3 mm spacing)--the others are Washington-Franklins, and some of the definitives from 1922.
