First American intervention
With a view to protecting the future routes of the Panama Canal, whose construction had already begun at the time, North American President Theodore Roosevelt tried to prevent by all possible means the European intervention that could take place due to the great Dominican debts with the old continent. For this reason, he proclaimed his famous Roosevelt Corollary  to the Monroe Doctrine, which in 1905 succeeded in taking control of the Dominican customs, the main source of income for the country at that time. The United States agreed to use part of the customs revenue to reduce the huge foreign debt of the Dominican Republic, and assumed responsibility for that debt.
After a period of civil war that followed the assassination of President Ramón Cáceres, who in turn had assassinated the dictator Heureaux, and due to pressure from the United States for the election of a president, a provisional president was elected, and later the same year in relatively free elections, former president Juan Isidro Jimenes Pereyra was elected. In order to achieve a government with more support, with identifiable persons, Jimenes appointed several opponents to his cabinet. But this did not bring peace, also with his former Secretary of War Desiderio Arias maneuvering to depose him and despite a US offer to help him militarily against Arias, Jimenes resigned on May 7, 1916.
On May 3, 1916,  Rear Admiral William Banks Caperton forced the Secretary of War of the Dominican Republic Desiderio Arias, who had taken office in the government of Juan Isidro Jimenes Pereyra, to leave Santo Domingo with the threat of a naval bombardment of the city. After the departure of Arias, the US Marines began the occupation of the country, controlling the entire nation two months after the intervention began. The Americans imposed a military rule under Rear Admiral Harry Shepard Knapp. With the North American administration, a highway system was built that linked all the regions of the country, the debt decreased and the economy was reactivated. Most of the Dominican institutions and laws were maintained during the occupation, however the repudiation of it never left the native population.
At the end of the First World War, Dominican discontent was joined with more force by that of American society. In 1921 The Harding Plan is presented, which advocated for the Dominican ratification of all acts of the military government, the approval of a US loan of $ 2.5 million for public works and other expenses, the acceptance of the US police officers – now known as the National Guard and the holding of elections under the supervision of the United States. This plan caused great discontent on the Dominican side, however it was used as the basis for a future negotiation that allowed the selection of a provisional president to govern until elections could be organized. The winner was former president Horacio Vásquez Lajara, who had cooperated with the US, Vasquez gave the country six years of good government, in which political and civil rights were respected and the economy grew strongly, in a calm environment.
The Trujillo dictatorship
According to Youremailverifier, Rafael Leónidas Trujillo joined the National Guard during the US occupation. Under the government of Horacio Vásquez he reached the rank of Lieutenant Colonel, Chief of Staff and Auxiliary Commander of the National Police.When Vásquez tried to win a new mandate, the opponents rebelled in February 1930, in a secret alliance with the Army commander Nacional (the old National Guard), General Rafael Leonidas Trujillo Molina, by which the latter remained “neutral” in the face of the rebellion, while Vásquez resigned and went into exile; Then Estrella Ureña is sworn in as provisional president on March 3, 1930. During the 5 months of president, all the laws that prevented Trujillo from aspiring to the presidency were repealed; In this way, Trujillo was able to aspire to the presidential elections of that time and not only that, but to all this was added the harassment and repression of all the candidates who aspired, as well as their followers. Trujillo rises to power on August 16, 1930, after the manipulations he did in complicity with Rafael Estrella Ureña, who was elected his vice president and abided by all his guidelines.
After the passage of cyclone San Zenón in 1930, he ordered the reconstruction and modernization of the Dominican capital, Santo Domingo, and renamed it Ciudad Trujillo, which would only recover its old name upon the death of the dictator. His dictatorship was characterized by disappearances and murders. Despite the economic growth that the country enjoyed during the Trujillo dictatorship, he came to have 60% of the Dominican budget under the control of his family and had the support of the United States for his anti-communism.
In the 1930s, it stimulated the immigration of European Jews to the Dominican Republic, not for humanitarian purposes but as an attempt to “whitewash” the native population, mostly mestizo. While promoting this European immigration, in 1937 he sent the army to the border with Haiti and assassinated more than 15,000 Haitians, under the pretext that the Haitian government supported Dominican exiles who sought to overthrow it.
Trujillo tried to intervene in the affairs of other Latin American nations, along with dictators Anastasio Somoza García (Nicaragua) and Marcos Pérez Jiménez (Venezuela). He supported the invasion of Rafael Angel Calderon to Costa Rica in 1955. After the overthrow of Pérez Jiménez, Trujillo’s political ally, he tried to overthrow the new Venezuelan government of Rómulo Betancourt, which applied its doctrine of not supporting foreign governments not elected by votes or with a militaristic tendency. On August 13, 1959 it was orchestrated by the Central Intelligence Agency, directly involving Batista criminals associated with the tyrant Rafael Leonidas Trujillo, an invasion of more than 1,500 men by Trinidad, at that time belonging to the province of Las Villas. The Rebel Army forces with the support of the entire Trinidadian people, and Led personally by Commander in Chief Fidel Castro, they crush the attempted counterrevolutionary invasion. Numerous weapons and supplies were seized from the enemy.
One of the most monstrous crimes of Trujillo was the murder of the Mirabal sisters, committed the 25 of November of 1960.Also ordered the attack on the then Venezuelan President Romulo Betancourt, the 24 of June of 1960, in which a military aide was assassinated and the president was seriously injured.
The 30 of maypole of 1961 a group of anti – Trujillo infiltrated his guard and supported by the CIA American, I executed them while traveling in his car.Some analysts mention that the interest of the United States to end Trujillo had to that the repression of their The government could bring a revolution similar to the Cuban one to the Dominican Republic.