A look at the complicated relationship between the United States and Cuba.
April 16, 1961: Castro declares his revolution is socialist. The next day, CIA-backed Cuban exiles try to invade Cuba at the Bay of Pigs, but are defeated.
October 1962: The United States discovers Soviet nuclear missiles on Cuba, leading to a showdown with the Soviet Union that almost leads to war.
April-October 1980: Cuba allows 125,000 people to travel to the United States from the port of Mariel in what becomes known as the Mariel Boatlift.
December 1991: The Soviet Union, Cuba's biggest benefactor, collapses, touching off an economic crisis from which the island has not fully recovered. REUTERS/Stringer
August-September 1994: More than 35,000 people leave Cuba in fragile boats, headed for the United States. REUTERS/Rolando Pujol Rodriguez
March 1999: The Clinton administration approves a two-game exhibition series between the Baltimore Orioles and Cuban national baseball team, marking the first time a Major League Baseball team played in Cuba since 1959.
September 1998: Five Cuban intelligence officers, known as the "Cuban Five," are arrested and later convicted of espionage, conspiracy to commit murder and other illegal activities in the U.S.
November 1999: Cuban child Elian Gonzalez is rescued from a capsized boat near the Florida coast, as he, his mother and her boyfriend attempted to reach the U.S.
2002: In the months after September 11, portions of the Guantanamo Bay Naval Base, which opened in 1903, are turned into a detention center for enemy combatants. REUTERS/Stringer
2004: Following George W. Bush's re-election, Secretary of State Condoleezza Rice declares Cuba to be one of the "outposts of tyranny" in the world. Later, Under Secretary of State for Arms Control and International Security Affairs John R.
July 31, 2006: Fidel Castro, seen here being visited by Venezuelan President Hugo Chavez, provisionally turns over power to his brother, Raul Castro, after undergoing emergency intestinal surgery. REUTERS/Estudios Revolucion-Granma/Handout
January 1, 1959: U.S.-backed dictator Fulgencio Batista flees Cuba as Fidel Castro (R, waving) and his revolutionaries seize control. Two years later, on January 3, 1961, the U.S.
February 24, 2008: The National Assembly elects Raul Castro to formally replace the ailing Fidel. REUTERS/Prensa Latina/Pool
December 10, 2013: Barack Obama and Raul Castro shake hands at a state memorial service for Nelson Mandela. REUTERS/Kai Pfaffenbach
December 2014: Cuba releases Alan Gross, 65, who had been imprisoned in Cuba for five years. Cuba convicted the U.S.
2013: Cuban and U.S. officials begin secret talks brokered in part by Pope Francis, and hosted in Canada and Vatican City. REUTERS/Carlos Garcia Rawlins
January 16, 2015: The United States rolls out a sweeping set of measures to significantly ease sanctions on Cuba, opening up the country to expanded U.S. travel, trade and financial activities.
July 1, 2015: Barack Obama announces formal diplomatic relations will resume, with embassies reopening in Washington and Havana. REUTERS/Alexandre Meneghini
August 14, 2015: U.S. Marines raise the American flag at the embassy in Cuba for the first time in 54 years, symbolically ushering in an era of renewed diplomatic relations between the two Cold War-era foes. REUTERS/Stringer
March 21, 2016: Barack Obama makes a historic trip to Cuba, the first visit by a sitting U.S. president since 1928. REUTERS/Jonathan Ernst
August 31, 2016: The first scheduled commercial passenger flight from the United States to Cuba in more than half a century lands. A JetBlue Airways Corp passenger jet arrived from Fort Lauderdale, Florida, in the central Cuban city of Santa Clara.
June 16, 2017: President Donald Trump ordered tighter restrictions on Americans traveling to Cuba and a clampdown on U.S.
September 29, 2017: The United States cut its diplomatic presence in Cuba by more than half and warned U.S. citizens not to visit because of mysterious "attacks" that have caused hearing loss, dizziness and fatigue in U.S. embassy personnel.