Carmelo Delgado Delgado Lieutenant Carmelo Delgado Delgado ( April 20 , 1913 – April 29 , 1937 ) was a leader of the Puerto Rican Nationalist Party ( presided by Dr . Pedro Albizu Campos ) . Delgado joined the Abraham Lincoln International Brigade and fought against General Francisco Franco and the Spanish Nationalists in the Spanish Civil War . The Republic ' s hero , Delgado Delgado , a Puerto Rican by birth and national origin , is thought to be the first U . S . citizen to die in Spain ' s civil war . Early years . Delgado was one of three siblings born to Eladio Delgado Berrios and Flora Delgado Gonzalez in the town of Guayama , Puerto Rico . He spent his early childhood on his parents ' farm located in the Guamani sector of the town and later moved with his family to the Calle ( Street ) Concordia esquina ( Corner ) Hostos in the town of Guayama . There he received his primary and secondary education . Puerto Rican Nationalist . Delgado enrolled and was accepted in the University of Puerto Rico , where he befriended Puerto Rican poet and Nationalist Juan Antonio Corretjer . Delgado became a pro - independence political activist and follower of Dr . Pedro Albizu Campos . He was a member of the " Cadets of the Republic " ( Cadets of the Republic ) , the youth organization of the Puerto Rican Nationalist Party . After earning his bachelor ' s degree , he moved to Spain in pursuit of a law degree . Spanish Civil War . On September 22 , 1935 , Delgado left for Spain and upon his arrival enrolled in the Central University of Madrid . He arrived in a Spain which was about to be confronted with a civil war between the government of the Second Spanish Republic and the pro - fascist Nationalist s led by the Nationalist General Francisco Franco . Delgado became politically active as a supporter of the Spanish Republic and upon the outbreak of the Spanish Civil War , joined the Abraham Lincoln International Brigade . The Abraham Lincoln Brigade was made up mostly of volunteers from the United States , which included Puerto Ricans and Cubans who served in the Spanish Civil War in the International Brigades . Delgado wrote to his friend , Puerto Rican Nationalist leader Carlos Carrera Benítez , the following letter : " Everyday I have more faith in our country ( Puerto Rico ) and I see the day coming when our people , like the people of Spain will take arms to squash the tyrants ( the United States ) with the same valor and resolution that the people of Spain have taken against their military and political traitors . " " How I wish that you were in Spain ! . I know that you would not stand with your arms crossed and that together we would write a page that would be considered an honor in our land and a motive of pride for the land of our grandfathers " " No one in Puerto Rico should know that I have joined the revolution " Delgado was involved in the Battle of Madrid , when he became unaware that his troops were ordered to retreat . He was captured and sent to Valladolid , where he faced a military war tribune . The United States Embassy offered to help , however Delgado refused their offer . According to Corretjer : " Carmelo Delgado preferred to die before a firing squad than to beg for his live to the " Yankee " ( in reference to the United States ) who had invaded his country " . Aftermath . Carmelo Delgado Delgado was executed on April 29 , 1937 by firing squad , becoming one of the first United States citizen s that died in that conflict . The news of his execution reached Puerto Rico and was posted on the front page of " El Mundo " newspaper on July 25 , 1937 as " Se confirma la ejecución del joven Carmelo Delgado " ( The execution of Carmelo Delgado , a young man , has been confirmed ) . Delgado ' s story has been narrated in the book " Galería de héroes de Puerto Rico " ( Gallery of Heroes from Puerto Rico ) by : José Morales Dorta . Military decoration . Carmelo Delgado Delgado was awarded the following : Further reading . " Galería de héroes de Puerto Rico " ; by : José Morales Dorta ; ISBN 1 - 56328 - 088 - 4 Delgado Cintrón , Carmelo ( Dr . ) ; " " Carmelo Delgado Delgado " " - Article by Carmelo Delgado Cintrón , Social History historian and legal historian of Puerto Rico