Costa Rican Civil War The Costa Rican Civil War was the bloodiest event in 20th - century Costa Rican history . It lasted for 44 days ( from 12 March to 24 April 1948 ) , during which approximately 2 , 000 people are believed to have died . The conflict was precipitated by the vote of the Costa Rican Legislature , dominated by pro - government representatives , to annul the results of the presidential elections held in February , alleging that the triumph of opposition candidate Otilio Ulate had been achieved by fraud . This caused a rebel army under commander José Figueres to rise up against the government of President Teodoro Picado , which it quickly defeated . After the war , Figueres ruled for a year and a half as head of a provisional government junta which abolished the military and oversaw the election of a Constitutional Assembly in December , which subsequently produced the new 1949 constitution . The junta then stepped down and handed power to Ulate . Costa Rica has not experienced any significant political violence since . Background . In the 1940s , the Costa Rican political scene came to be dominated by Rafael Ángel Calderón , a medical doctor who served as President of Costa Rica from 1940 to 1944 . < / sup > The Constitution forbade consecutive reelection , so Calderón ' s National Republican Party had fielded as its candidate for the 1944 elections law professor Teodoro Picado , who was perceived as a weak figure controlled by Calderón . The Picado administration resorted several times to the use of military force in order to keep the peace , and pro - Calderón elements within the military institution would often become involved in street violence , which helped to sully the image of the military in the minds of the people . The Costa Rican communist movement , organized in the Popular Vanguard Party led by congressman Manuel Mora , was allied to Picado ' s government and contributed to the unrest by deploying its militia against the opposition . As the violence grew , supporters of the opposition began to carry guns , and the police began to threaten the use of firearms rather than just beating demonstrators . Disgust with the government ' s violent reprisals against the opposition led to the " Huelga de Brazos Caídos , " a strike that stalled commerce in Costa Rica for seven days . Pro - Calderón and communist demonstrators began to sack those businesses that participated in the strike , and Picado was forced to respond to the strike with force by intimidating merchants and professionals and threatening workers with dismissal and military service . By the end of the strike , police and military forces patrolled the streets , and San José appeared as if under a state of siege . < / sup > Calderón himself was the ruling party ' s candidate for the election of 1948 and there were widespread fears that the government would intervene to ensure his triumph against his main opponent , journalist Otilio Ulate . < / sup > To assuage these fears , Picado ' s government for the first time in Costa Rican history placed the election under the control of an independent Electoral Tribunal . Figueres and the Caribbean Legion . José Figueres , a Costa Rican businessman , had been forced into exile in Mexico on April 12 , 1942 as a consequence of a radio broadcast in which he strongly criticized the Calderón regime . Figueres had returned to Costa Rica after the election of Picado . Before the elections of 1948 , Figueres had already been planning for a war . Unlike Ulate , former president León Cortés , and the other members of the Costa Rican opposition , Figueres felt that Calderón would never allow a fair election to take place . Figueres began training the Caribbean Legion , an irregular force of 700 . Hoping to use Costa Rica as a base , the Legion planned to move against other authoritarian governments in Middle America . Washington , D . C . officials followed the Legion ’ s activities with concern , especially after Figueres carried out a series of terrorist attacks inside Costa Rica during 1945 and 1946 that was supposed to climax in a general strike . But the people did not respond . < / sup > 1948 elections and violent aftermath . After a highly contentious electoral process plagued by violence and irregularities concluded on February 8 , 1948 , the independent Electoral Tribunal , by a split vote of 2 to 1 , declared that opposition candidate Otilio Ulate , of the National Union Party , had been elected president . The National Republican Party candidate , former President Calderón , claimed that this result had been obtained by fraud and petitioned Congress , where the coalition of his own party and the communist Popular Vanguard Party held a majority , to void the results and call for a new election . When Congress granted this request the country erupted in chaos , as both sides accused the other of vote tampering and electoral fraud . On the day that the government annulled the elections , police surrounded the home of Dr . Carlos Luis Valverde , where Ulate was and Figueres had been only moments before . Shots rang out , and Valverde fell dead on his doorstep . Ulate escaped but was later captured and imprisoned , all of which helped to paint an especially distasteful image of the military . < / sup > Beginning of Civil War . The annulment of the election results in 1948 and the attack on Dr . Valverde ' s home on the same day appeared to provide for Figueres the proof that he needed to show that the government had no intention of ceding to the will of the people . His hatred for Calderón , combined with his idealism , fueled his desire for war . On March 11 , Figueres made the call that brought in the arms and military leaders Figueres needed for a successful campaign . On March 12 , his National Liberation Army exchanged fire with government forces , and the war began . < / sup > Ideological context . Costa Rican politics have traditionally been guided by personal allegiances far more than by ideological consistency , and the Civil War of 1948 provides a striking example of this . Calderón had been elected president in 1940 as the candidate of the right , closely allied with the Roman Catholic Church and with the business elite , but his enthusiastic support for the Allies during World War II and especially his punitive measures against the rich and influential German community in Costa Rica , caused that elite to withdraw its support for him . Calderón then created a different political base by allying himself with the Costa Rican communists ( the Popular Vanguard Party ) , led by Manuel Mora , and with the socially - progressive Catholic Archbishop of San José , Monsignor Víctor Manuel Sanabria , in order to pass legislation guaranteeing labor rights and creating a welfare state . Mora ' s communist militias provided important armed support for the government , both during the tense years of Picado ' s administration ( 1944 – 48 ) and during the Civil War itself . The rebel forces led by Figueres were a disparate mix of anti - communist right - wingers , economically conservative elements weary of the welfare state ( represented by the winner of the 1948 election himself , Otilio Ulate ) , and a social democrat intelligentsia which sought to strengthen the welfare state while ensuring democratic transparency . After their victory this alliance quickly fell apart . The right - wing faction , led by the junta ' s Minister of Public Safety , Édgar Cardona , attempted to overthrow Figueres and was excluded from the government thereafter . Figueres himself became closely identified with the social democrat faction , which later dominated his own National Liberation Party ( PLN ) . The economically conservative groups under Ulate ended up allying themselves in the 1950s with Calderón ' s supporters to form a broad anti - PLN coalition . This lack of ideological consistency is further underscored by the fact that during the Civil War the government forces , despite being allied to the Costa Rican communists , enjoyed the support of right - wing Nicaraguan dictator Anastasio Somoza , while Figueres ' s rebels , who as anti - communists were tacitly supported by the United States , received significant aid from leftist Guatemalan president Juan José Arévalo . Fall of Cartago . The National Liberation Army , as the rebel army called itself , slowly worked their way up the Pan American Highway , capturing small but important cities and ports with relative ease . The official army , which was then led by Picado ' s brother , was unable to organize an effective resistance to Figueres ' National Liberation Army . Figueres also contended against the communist militias commanded by congressman Carlos Luis Fallas and against Nicaraguan soldiers who had been sent by Somoza to help the government retain power . In Cartago , Costa Rica ' s second - largest city located only twelve miles from the capital , Figueres ' forces met some considerable military opposition ; however , the limited forces and supplies of the governmental forces quickly ran out , and Cartago fell into the hands of Figueres on April 12 . Costa Rican President Picado , realizing that defeat was inevitable , sent notice to Figueres that he was willing to come to a compromise . Picado ' s long - time political ally , Manuel Mora of the communist Popular Vanguard Party , had no intention of negotiating with Figueres . Mora ' s forces had sealed themselves up inside the capital of San José , and were determined not to capitulate as quickly as Picado . As the target of many of Figueres ' criticisms about Costa Rica , Mora and his party were worried that a Figueres - led takeover might well lead to their expulsion from politics . Figueres and United States policy . Arévalo ' s help proved to be indispensable . The determining force was United States policy . The creators of that policy held little love for Figueres , but they were determined to destroy the ‘ ’ Vanguardia Popular ’ ’ . Perhaps the Communist party had only seven thousand members , Ambassador Davis reported home , but it should hold the balance of political power in Congress and also constituted “ some 70 percent of the police and army . ” Writing within hours after the Communist overthrow of the Czechoslovak government ( an event that severely shook Washington and other Western capitals ) , Davis warned that Costa Rica ' s condition was “ in many respects similar to that prevailing in Eastern Europe . ” When the State Department learned on 17 April 1948 that small Communist groups threatened to take over the capital of San José , US troops were placed on alert in the Canal Zone . Their mission was to move quickly into Costa Rica and stop the revolution before the Vanguardia Popular consolidated its power . It was a false alarm , but it indicated that regardless of any Good Neighbor policy sentiments , the possibility of unilateral U . S . intervention was no mere abstraction . Throughout the conflict , Figueres received a steady supply of arms from Arévalo , while Picado ’ s forces were unable to exploit Somoza ’ s desire to help . The United States had ensured Somoza ’ s political impotence . Desperately wanting Nicaraguan help , Picado pleaded with Ambassador Davis to allow what was , after all , the recognized Costa Rican government to obtain help from Nicaragua so it could remain in power . Davis blandly “ explained our well known policy of non - intervention ” and then referred to the obligations of American nations [ to ] non - intervene . ” Picado bitterly observed that non - intervention was a fiction , Figueres had received “ tons ” of supplies from Arévalo , and rumors circulated of aid even from the Panamanian government . Davis ignored the charges . Picado then threatened to take the matter to the United Nations . “ The United Nations machinery was cumbersome , ” the State Department suavely but directly reminded the Costa Rican leader , and “ immediate action on the part of the Council [ Where the United States had a veto and controlled the majority of the votes ] could probably not be expected . ” Surrender of Picado . The day after the fall of Cartago , Picado — low on supplies and without any other source of support — sent a letter to Mora and National Republican leader , and former President Calderón stating that " the attempt to hold San José would be futile and catastrophic . " Mora , facing the reality that now the United States was ready to act against him as well , gave in to Picado ' s plea . On April 19 , Picado and Father Benjamín Núñez , an eminent labor leader within Costa Rica , signed The Pact of the Mexican Embassy , ending the armed uprising . On 24 April , Figueres ' forces entered San José , almost six weeks after beginning their revolt in southern Costa Rica . By its mobilization in the Canal Zone , constant pressure on Picado , and cutting off Somoza ’ s help , the United States determined the outcome of the revolution in April 1948 . With more than 2 , 000 dead , the 44 - day civil war resulting from this uprising was the bloodiest event in 20th - century Costa Rican history . Civil War repercussions . Despite the fact that this civil war alone was relatively small in scale - its duration was short and about two thousand casualties - its consequences have had lasting results on the country and the region as a whole .