This image was taken by Edwin Rosskam in the San Juan area, in December 1937.
The image contains a few points of interest.
It is very much “a guy thing.” Over fifty men, but not one woman appears in the photo.
Class and racial stratification is suggested. There are more suits sitting in the first row, and no black men. The darkest-looking man appears in the fourth upper row.
Overhead scoop lights make “night fights” possible.
Two insular policemen mingle with the crowd. Four years earlier, on May 9, 1933, the new Governor of Puerto Rico, Blanton Winship, legalized cockfighting in Puerto Rico.
Just a few months before this photo, Gov. Winship and his insular police force killed 17 Puerto Rican civilians and wounded over 200 more, in the Ponce Massacre.