The United States has intervened in the affairs of Latin American countries in many instances over the past century and more. Major US interventions started in the late 1800s and early 1900s.
One example of a country in which the US intervened more than once is Panama. In the early 1900s, the United States intervened to help Panama become a country. It did so because it wanted to build the Panama Canal. The area that is now Panama was then part of Colombia and the US did not like the terms that Colombia was demanding for the canal. Therefore, the US intervened and helped Panama become independent. The US then built the Canal. Decades later, the US invaded Panama in the late 1980s. This was done, according to the US government, to protect democracy and human rights and to reduce the amount of drug smuggling that was being done. The Panamanian ruler, Manuel Noriega, was removed from office and brought to the United States to stand trial for drug trafficking. He served time in the US and in France and is now in prison in Panama.
The Spanish-American War was an intervention in the affairs of Latin America.
It began with Spain trying to put down rebellions against its rule in Cuba, Puerto Rico, and the Philipines. The US dispatched the USS Maine to Havana, amid reports of threats to US interests in Cuba. On Feb. 15, 1898, less than a week after its arrival, the Maine mysteriously blew up in the middle of the night. Blame for the disaster immediately fell on the Spanish, and the Congress passed resolutions declaring that any further Spanish intervention constituted a violation of the Monroe Doctrine. When the King of Spain rejected the resolutions, US forces invaded Cuba, Puerto Rico and the Philipines, assisting the rebels.
More recently was the invasion of Granada in 1980. The Capitalist Granadan government was overthrown by a socialist uprising. Then President Ronald Reagan dispatched troops to the island nation to prevent a communist dictatorship from being established.