On this day in ...
... 1961, having been concluded in 1959, the Antarctic Treaty entered into force, as proclaimed this same day by U.S. President John F. Kennedy. Days later, the 1st consultative meeting of the 12 states parties to the treaty (prior posts) was set for the following month in Canberra, Australia. (credit for treaty system logo at right)
(Prior June 23 posts are here, here, and here.)