There are a hundred threads in which this is discussed. JFK did not kill the hat.
Lefty said:Not true.
We've had many threads that talk about hats really starting to die out well before WWII. Check out some of these articles, particularly this one:
Third Source
E. J. Kahn, The Talk of the Town, "Hats On," The New Yorker, September 28, 1946, p. 19
Talk. Stanley expedition to Danbury for an investigation of men's hatlessness. N. Y. is the most hatless city in the country. Danbury itself is not 100% hatted. Factories used to have a rule no employees could come to work hatless; buyers, however, are instructed not to interview hatless salesmen. Twelve per cent of all men never wear hats. 32% always wear hats. 98% of all men over 45 own at least one hat. Only 70% of college men own hats. Only 62% of college men consider hats important to personal appearance, veterans, 68% of them, do. Early in this century U. S. had 25 million males old enough for hats, and the annual production was 36 million; just before the war 50 million hat-males, but production of felts only 22 million. 59% of the women dislike hatless men. Goes into the question of baldness because of hats.
As to the hat comeback, here it is in 1982, and again in 1999.