Camp Las Casas Camp Las Casas was a United States military installation established in Santurce , Puerto Rico in 1904 . The camp was the main training base of the " Porto Rico Regiment of Infantry , " a segregated U . S . Army Regiment which was later renamed the " 65th Infantry Regiment . " The base continued in operation until 1946 , when it was finally closed . History . Prelude . After the Spanish - American War ended , Puerto Rico was annexed by the United States as a result of the Treaty of Paris of 1898 , ratified on December 10 , 1898 . Spain had lost its last colony in the western hemisphere and the United States gained imperial strength and global presence . The United States established a military government and appointed Major General Nelson A . Miles the first head of the military government established on the island , acting as both head of the army of occupation and administrator of civil affairs . On January 15 , 1899 , the military government changed the name of Puerto Rico to " Porto Rico . " The Army Appropriation Bill created by an Act of Congress on March 2 , 1889 authorized the creation of the first body of native troops in Puerto Rico . On June 30 , 1901 , the " Porto Rico Provisional Regiment of Infantry " was organized . On July 1 , 1901 , the United States Senate passed a Bill which would require a strict mental and physical examination for those who wanted to join the Regiment . Under the provisions of an act of Congress approved April 23 , 1904 and of Circular No . 34 , War Department , July 29 , 1904 , the recruitment of native Puerto Rican civilians to be appointed the grade of second lieutenant s for a term of four years , was approved with the condition that they pass the required tests . The " Porto Rico Provisional Regiment of Infantry " was renamed the " Porto Rico Regiment . " Though many civilians from all walks of life applied for the officers ' appointment on January 1905 , only seven made it that day . One of them was Teófilo Marxuach who , from 1903 to 1905 , had worked as a civil engineer for the Porto Rico Regiment in the Aqueduct of Cayey . An Act of Congress , approved on May 27 , 1908 , reorganized the regiment as part of the " regular " Army . Since the native Puerto Rican officers were Puerto Rican citizens and not citizens of the United States , they were required to undergo a new physical examination to determine their fitness for commissions in the Regular Army , and to take an oath of U . S . citizenship with their new officer ' s oath . World War I . Camp Las Casas was established in Santurce under the command of Lt . Colonel Orval P . Townshend in 1904 . The Porto Rico Regiment , which consisted of two battalions of the former Porto Rico Provisional Regiment of Infantry , was assigned to the camp . The first shot of World War I by the U . S . is fired . On March 21 , 1915 , Lt . Marxuach , of the Porto Rico Regiment , was the officer of the day at El Morro Castle ( Fort San Felipe del Morro ) . The " Odenwald , " built in 1903 ( not to be confused with the German World War II war ship which carried the same name ) , was an armed German supply ship which tried to force its way out of the San Juan Bay and deliver supplies to the German submarines waiting in the Atlantic Ocean . Lt . Marxuach gave the order to open fire on the ship from the walls of the fort . Sergeant Encarnacion Correa then manned a machine gun which was located along the wall below " La Fortaleza , " the governor ' s residence and fired warning shots at the ship with little effect . Marxuach then fired a shot from a cannon located at the Santa Rosa battery in the upper platform of " El Morro , " in what is considered to be the first shot of World War I fired by the regular armed forces of the United States against any ship flying the colors of the Central Powers , and it forced the " Odenwald " to stop and to return to port , where its supplies were confiscated . The Porto Rico Regiment was a segregated unit made up mostly of Puerto Ricans . Puerto Ricans were unaccustomed to the racial segregation policies of the United States which were also implemented in Puerto Rico , and often refused to designate themselves as " white " or " black . " This was the case with Antonio Guzman who was assigned to a white regiment , then reassigned to a black regiment at Camp Las Casas . He requested a hearing and argued his case to no avail . Captain Luis R . Esteves , the first Hispanic to graduate from the United States Military Academy at West Point , was sent to Camp Las Casas in Puerto Rico and served as an instructor in the preparation of Puerto Rican Officers for the Regiment . In 1916 , the military strength of the Porto Rico Regiment increased with the creation of machine gun and supply companies and the organization of a 3rd battalion . On January 30 , 1917 , Puerto Ricans Manuel B . Navas , Enrique M . Benitez , Vicente N . Diaz , Andres Lopez , Ramon S Torres , Modesto E . Rodriuez and Ernesto F . Colon were appointed to serve as Second Lieutenants of the Porto Rico Regiment . On March 2 , 1917 the U . S . Congress approved the Jones - Shafroth Act , which imposed United States citizenship with limitations upon Puerto Ricans ( the Puerto Rican House of Delegates rejected US citizenship ) , and rendered them immediately subject to be drafted , in order to fight in World War I . On April 6 , 1917 , the U . S . Congress declared war on Germany and on May 3 , 1917 , the Regiment recruited 1 , 969 men , considered at that time as war strength . When the United States entered the war , the U . S . Army Medical Corps believed that they had enough male physicians to cover their needs . Dr . Dolores Piñero applied for a position as a contract surgeon only to be turned down . After writing a letter to the Army Surgeon General in Washington , D . C . explaining her intentions , she received a telegram ordering her to report to Camp Las Casas where she was assigned to the Medical Service Corps of the Army Medical Department . Dr . Piñero became one of the first female doctors to work under contract for the U . S . Army . However , contract physicians had little status within the military . They did not wear uniforms and had little authority . Captain Luis Esteves , instructor and trainer of the Puerto Ricans who served as Officers in the Regiment , helped organize the 23rd Battalion composed solely of Puerto Ricans , for deployment . On May 14 , 1917 , the Porto Rico Regiment was sent to Panama in defense of the Panama Canal Zone . It is estimated that , while in Panama , 335 Puerto Ricans were wounded by the chemical gas experimentation which the United States conducted as part of its active chemical weapons program . The Regiment returned to Puerto Rico on March 1919 and was renamed the " 65th Infantry Regiment " by the Reorganization Act of June 4 , 1920 . In 1919 , Félix Rigau Carrera , also known as " El Águila de Sabana Grande " ( The Eagle from Sabana Grande ) , made a historical flight out of Camp Las Casas by becoming the first pilot to fly an air mail route . By that time ( 1919 ) , Camp Las Casas was also being used as an air base . World War II . On May 17 , 1932 , U . S . Congress changed the name of the island from " Porto Rico " back to " Puerto Rico . " In 1937 Japan invaded China , and in September 1939 Germany invaded Poland . During that period of time , Puerto Rico ' s economy was suffering from the consequences of the Great Depression , and unemployment was widespread . This unemployment was one of the reasons that some Puerto Ricans chose to join the Armed Forces . Most of these men were trained in Camp Las Casas , and assigned to the 65th Infantry Regiment . As rumors of war spread , and U . S . involvement appeared more imminent , the 65th Infantry was ordered to intensify its maneuvers . Many of these were carried out at Punta Salinas near the town of Salinas in Puerto Rico . Those who were assigned to the 295th and 296th regiments of the Puerto Rican National Guard received their training at Camp Tortuguero , near the town of Vega Baja . The 65th Infantry Regiment continued to train at Camp Las Casas under the command of Colonel John R . Mendenhall . On November 25 , 1943 , Colonel Antulio Segarra succeeded Colonel Mendenhall and assumed the command of Puerto Rico ' s 65th Infantry Regiment , which at the time was conducting security missions in the jungles of Panama . Thus , Segarra became the first Puerto Rican Regular Army officer to command a Regular Army Regiment . On January 1944 , the Regiment was embarked for Jackson Barracks in New Orleans and later sent to Fort Eustis in Newport News , Virginia in preparation for overseas deployment to North Africa . After they arrived at Casablanca , they underwent further training . By April 29 , 1944 , the Regiment had landed in Italy and moved on to Corsica . On June 21 , 1944 , Segarra was succeeded by Col . Paul G . Daly , in command of the 65th Infantry Regiment . The American participation in the Second World War came to an end in Europe on May 8 , 1945 when the western Allies celebrated " V - E Day " ( Victory in Europe Day ) upon Germany ' s surrender , and in the Asian theater on August 14 , 1945 " V - J Day " ( Victory over Japan Day ) when the Japanese surrendered by signing the Japanese Instrument of Surrender . On October 27 , 1945 , the 65th Infantry , which had participated in the battles of Naples – Fogis , Rome – Arno , central Europe , and of the Rhineland , sailed home from France . Arriving at Puerto Rico on November 9 , 1945 , they were received by the local population as national heroes and given a victorious reception at the Military Terminal of Camp Buchanan . Afterwards , the Regiment returned to Camp Las Casas . Post - World War II . After the war the United States reduced its military force and Camp Las Casas closed in 1946 . In 1950 , a public housing project named Residencial Las Casas was built in the area where the camp once stood . Notable people who served in Camp Las Casas . Among the notable people whose actions at one time or another have been linked to Camp Las Casa were the following : Other military articles related to Puerto Rico :