The photo was sent to U.S. Congress . On March 21 , 1937 , a Palm Sunday , the cadets were to participate in a peaceful march scheduled in the city of Ponce . The march had been organized by the Puerto Rican Nationalist Party to commemorate the ending of slavery in Puerto Rico by the governing Spanish National Assembly in 1873 . The march was also protesting the imprisonment , by the U.S. government , of Nationalist leader Albizu Campos on alleged sedition charges . Díaz Pacheco , who by then was the '' Comandante '' ( Commander ) of the Cadets of the Republic , and his brother Faustino were present when this peaceful march turned into the bloody police slaughter , which became known as the Ponce massacre
Ponce massacre
Ponce massacre
Raimundo Díaz Pacheco