Is The Blue Boy The World's First Round Postage Stamp?

Although an American classic, is it a world first?

I bumped into this yesterday

https://blog.delcampe.net/en/discov...medium=email

and then went on to find this

https://goscf.com/t/25689

Has any more information regarding these stamps been published?

Has anybody any idea when the next round stamp rolled on along?

No .....seals and markings have been around for thousands of years.Letter carriers have been recorded for centuries .

The first circular stamps were the "Scinde Dawks" 1852
Only the first printing was a circular,
the later came in sheets and were usually cut square.

Circular were then issued by the Indian native states
Indore 1889
Kashmir 1866
The registration stamps of Colombia 1865
Afghanistan 1871 (also cut square)

The first true "circular" stamps since then are the "Beermats" of Tonga (June 1963)

The blue boy was a provisional.

The Bermuda Cotton Reels were issued in 1848. Not sure if they were regular issues or provisionals, though.