Puerto Rico, December 1937. "The beginning of the cockfight. When the man in the center raises the cloth, the birds will see each other and begin to fight." Medium format nitrate negative by Edwin Rosskam for the FSA. View full size.
Cockfights were still allowed in Puerto Rico, at least when I visited a few years ago. I tend to doubt the spectators would be dressed in so dapper a fashion nowadays, though.
It's a gateway sport...
...and it leads to cat juggling.