Short answers, pulled from the story.
The United States attempted to purchase Cuba from Spain in 1848. President James K. Polk sent his minister Romulus Mitchell Saunders on a mission to offer this sum.
Senator Orville H. Platt authored the Platt Amendment to the 1901 Army Appropriations Act which allowed the United States to intervene in Cuban affairs. It required Cuba to lease land for naval bases including the southern portion of Guantánamo Bay established as a United States Naval Station in 1898.
Over 75 people died when the French freighter La Coubre exploded in Havana Harbor in March 1960. Fidel Castro blamed the United States but admitted he could provide no evidence regarding the cause of the explosion.
Formal diplomatic relations were re-established on the 20th of July 2015 following an agreement framework announced by Fidel Castro and Barack Obama on the 17th of December 2014. The Cuban embassy opened in Washington and the U.S. embassy in Havana shortly thereafter.
President Donald Trump declared a national emergency regarding Cuba on the 30th of January 2026 establishing tariffs on countries supplying oil. This action followed previous restrictions enacted in November 2017 and further travel limits announced in June 2019.