[3] He was a student for three years at Brooklyn's Commercial High School and also studied Spanish at Columbia University's extension department.

Franklin's nickname acknowledged his Jewish heritage: El Torero de la Torah.

[3] In Death in the Afternoon, Hemingway wrote: he is one of the most skillful, graceful and slow manipulators of a cape fighting today.

[6]Author Ernest Hemingway on Franklin’s fluency in the languages of Spain: “He speaks Spanish so grammatically good and so classically perfect, with all the slang and damn accents and twenty-seven dialects, that nobody would believe he is an American.

[1] According to A. E. Hotchner, "Lillian Ross's career with The New Yorker was founded on the success of her profile of the bullfighter Sidney Franklin.

[5] He was a close friend of the American actor James Dean, who was a big fan of the art of bullfighting.

[citation needed] Franklin was gay, his sexual identity having been an open secret among those who knew him, but remaining unknown to the public.