Boxing was introduced and practiced in a clandestine manner in Puerto Rico while the archipelago was still a Spanish colony. Fights were organized in haciendas among the workers of the sugar and coffee plantations, and the objective was to determine the best fighter among the employees. Following the culmination of the Puerto Rican Campaign and Spanish–American War, American soldiers who were stationed in the main island practiced the sport. During World War I, a championship known as Campeonato Las Casas was held as training for military personnel. Nero Chen, the first Puerto Rican boxer to gain recognition, began his career in these tournaments. The Combat Maneuver Training Center followed this example and organized boxing activities, which they named Los Campeones del Campamento. These were received with enthusiasm by the young recruits. Most of these events were celebrated without restriction due to military jurisdictional limits, although prohibitions were put in place for the civilian population. Illegal matches were organized on the rooftops of residences in Old San Juan, empty terrain's in El Condado and in hippodromes. Outside of the island, legendary opera tenor Antonio Paoli, fell on economic hardship due to the closing of european opera houses during the first world war. He decided to change careers and entered a period of training making his boxing debut in London in 1916. Paoli won his first 5 fights but injured his wrist in his 6th bout, deciding to retire. The fact that a celebrity of his stature, who had been bestowed honors for his musical prowess by the pope, the spanish monarchs and the russian czar, would so quickly choose boxing as an alternate career shows how popular and deeply embedded in the culture of the island boxing was, even during its clandestine era.https://en.m.wikipedia.org/wiki/Antonio_Paoli By 1924, several young men were being taught to box by Gregario Rosa, a boxer who had won the featherweight championship of the Atlantic Fleet while serving in the Navy. Rosa established "Jack Dempsey Physical Culture and Boxing Club", a gym where he continued instructing more pugilists; however, the local police department would go in and arrest any boxer that participated in a card (organized boxing match). At times they were surprised to discover that several members of the law enforcement agencies and government were involved. In one case they discovered a group of police officers, including a colonel, two members of the governor's cabinet, numerous legislators and