and beginning a new era between the two countries.

But to understand just how big of a deal , where that hostility really came from, and why it

took so long to end, you've go to go back — way back, not to the 1950s as many Americans

think, but to the 1850s.

The story starts with America divided between pro-slavery and anti-slavery politics.

And one of their many fights is over the Spanish colony of Cuba.

Pro-slavery lawmakers want to buy Cuba from Spain, or take it by force, to turn into a

new slave state.

Anti-slavery politicians oppose this, calling it imperialism.

In 1898, after slavery ends, Americans have a different version of this argument again,

when Cubans rise up against Spain.

The US joins them, starting the Spanish-American war.

But Americans divide: should the US seize Cuba from Spain for itself, or liberate it?

This is part of a much bigger debate at the time over whether the US should explicitly

become a European-style imperial power.

So this is an argument about Cuba, but it's also an argument about America and what kind

of country it should be.

Should America be the kind of country that controls Cuba, or that respects it as a fellow

sovereign nation?

That argument has continued, in different forms, ever since

At this point, in 1898, the fight happens in Congress.

Each side passes laws trying to force their way.

It ends with a weird split-baby policy, with Cuba winning independence, but under quasi-imperial

rule.

The US would take over Guantanamo Bay, dictate Cuba's foreign policy, and give itself the

right to intervene in Cuban affairs.

Then come the next American interventions in Cuba, in 1906 and 1917.

Each time, the US military takes over for a few years, ostensibly to resolve some political

crisis, but that usually means protecting American interests, such as sugar imports.

Today, when Americans think about the US and Cuba, we think of the Cold War, but Cubans

often think back to this imperial era.

That era technically ends in 1933, with an uprising against Cuba's government.

Under US law, America is supposed to intervene, but President Franklin Roosevelt want to end

America's imperial era, so he declares neutrality.

Over the next 20 years, Cuba becomes a democracy, and one that's generally friendly with the

US.

That changes in 1952, when a former president and military leader named Fulgencio Batista

seizes power in a coup, suspends the constitution, and imposes an increasingly oppressive rule.

Cuba's Communist uprising begins the next year, led by a young Fidel Castro.

American politics at this point is obsessed with fears of communism, so the US backs Batista

in the war, no matter how brutal he becomes.

For Americans, this feels like a front in the struggle against communism.

But for Cubans, it feels like Batista is an extension of American imperialism, and the

guerrilla war a continuation of their long fight for freedom.

The communists win in 1959 and Castro takes power.

The US, fearing communism's expansion, sets up the embargo to strangle Cuba's economy,

tries to assassinate Castro, even, in the disaster known as Bay of Pigs, sends in CIA-trained

Cubans to try to take over the island.

Castro turns to the Soviets for help, and in 1962 they nearly start World War Three

when the US blocks Soviet efforts to put nuclear missiles in Cuba.

The incident scares everyone enough that things settle into a tense but peaceful status quo.

Over time, ordinary Cubans are squeezed between the US embargo and Castro's dictatorship.

In 1980, Castro tries to relieve some political dissent by briefly allowing Cubans to leave

the island, and 125,000 arrive in Florida.

No one realizes it at the time, but this adds a completely new dimension to the conflict.

It's now also about the internal Cuban battle between Castro and Cuban dissidents, which

plays out through American politics.

This becomes really important in the 1990s.

After the Soviet Union collapses, President Clinton, seeing Cuba poses no threat, wants

to end the conflict.

So does Castro, who can't count on Soviet aid any more.

But Cubans in America, who suffered terribly at Castro's hand, want to see him fall, and

push for keeping the embargo.

In 1996, Cuba shoots down two private planes chartered by Cuban-American activists.

There's a big backlash in the US, and Clinton backs down.

20 years later, President Obama tries again to end the conflict.

By now, Americans don't really support the embargo.

Lots of Cuban-Americans are now economic migrants, rather than political exiles, so they want

openness.

Fidel is getting old, and in 2008 hands power to his brother Raul, who knows the country

needs to change.

The US and Cuba start secret talks in 2013.

The new Pope, Francis, helps negotiate.

In 2014, they reveal their agreement to end the conflict, and the next year Obama becomes

the first president to visit since Calvin Coolidge in 1928.

The US and Cuba have never really had "normal" relations until now, and that's crucial to

understanding why it took so long for this to happen.

So much has passed between the two countries over the past century, and the US has at times

treated Cuba as more of a colony than a real country.

It's a lot to get over.

But it looks like they might both finally be ready.