From episode #92, The Case of the Slandered Submarine

Note the pattern of the the stars. That's a 48-star flag! Not
appropriate at all for a 5/18/60 show. Remember? Alaska
came in on 1/3/59 and Hawaii on 8/21/59.

Not exactly! Please read the second part of this trivia item.
Because of an executive order by President Eisenhower,
the 50 star flag did not become active until July 4, 1960. In
addition, is was required that existing flags be used until

[Trivia][Perry Mason TV Series]