In 1959, Marqués published three plays together in the collection "Teatro" (Theater). These were "La Muerte no entrará en Palacio" (Death will not enter the Palace), "Un Niño Azul para esa Sombra" (A Blue Boy for that Shadow) and "Los Soles Truncos". In an essay (1960), which the Puerto Rican Nationalist Party published as a pamphlet, Marqués addressed the problem of the language of instruction in Puerto Rico's colonial situation. He concluded that only the enjoyment of complete national sovereignty will cleanse the pedagogical problem of all extra-pedagogical baggage.