In the mid-twentieth century, violence fueled by Gaitán's assassination, political polarization, the Rojas Pinilla dictatorship, and the imposition of the National Front led Arango to produce a series of works alluding to April 9 and the fall of Laureano Gómez. Some experts see this period of artistic production as containing references to Goya, with grotesque creatures from the animal world representing figures from Colombian politics.