
Cuba had been on the U.S. radar since the times of Thomas Jefferson. In 1848, James Buchanan, on behalf of President James K. Polk, offered to purchase Cuba from Spain for $100 million. Spain turned down the offer.
Franklin Pierce was elected president in 1852 and filled his cabinet with pro-slavery figures, including Jefferson Davis as Secretary of War. Most of his ambassadors also supported slavery. Many of these individuals, key players in U.S. foreign policy, advocated for slavery-based imperialism. The three authors of the Ostend Manifesto were all slavery supporters.
In his inaugural address, Pierce stated that the acquisition of Cuba was a top priority for his administration. Rumors that Spain was planning to abolish slavery on the island greatly alarmed the Pierce administration. Emancipation in Cuba could have triggered a chain reaction in the American South.
In October 1854, the Ostend Manifesto was drafted by three U.S. diplomats stationed in Europe: James Buchanan (in the United Kingdom), John Y. Mason (in France), and Pierre Soulé (in Spain). Soulé was a so-called fire-eater, an ultra-conservative from the Deep South. The Manifesto proposed purchasing Cuba from Spain and stated that, should Spain refuse, the U.S. would be justified in taking the island by force.
Background and Content 📝
In March 1854, the Black Warrior incident—involving the seizure of an American ship in Havana—heightened tensions between Spain and the United States.
In October 1854, Buchanan, Mason, and Soulé met in Ostend (Belgium) and later in Aix-la-Chapelle (Prussia) to discuss the Cuban question.
The document argued that the United States should make a serious and immediate effort to acquire Cuba at any cost. Cuba’s geographical location was deemed critical: it dominated the mouth of the Mississippi River and the growing commerce flowing into the Gulf of Mexico.
The authors argued that as long as Cuba remained under distant Spanish control, U.S. commercial and strategic interests would be at risk. They framed the acquisition as a mutually beneficial transaction: Spain would receive substantial financial compensation, which could help develop its natural resources.
However, the Manifesto also raised the specter of racial fears. It warned that Cuba might “Africanize” like Santo Domingo (now Haiti), leading to a race war that would threaten the white population of the South. This echoed white supremacist and pro-slavery ideologies pervasive in Southern U.S. politics.
The Black Warrior affair was cited as a “red-handed outrage” against American citizens and, according to the Manifesto, justified retaliation or even war.
Implications, Public Reaction, and Fiasco ⛔
At the time, Cuba was seen by many in the U.S. as a strategic point for both national security and expansionist aims. The authors feared that a slave rebellion in Cuba might inspire similar uprisings in the American South.
The Ostend Manifesto is a clear expression of America’s ambition to become a colonial power, aligning with the filibuster ideology—private, unauthorized efforts to conquer Latin American territories.
Though framed as a “liberation” mission, the Manifesto’s real purpose was domination. Many Cubans, meanwhile, were fighting for genuine independence.
When the Manifesto was leaked to the press in 1855, it sparked outrage, particularly in the North, where it was seen as a pro-slavery expansionist plot. It deepened sectional tensions in the lead-up to the Civil War.
As a result, the initiative was shelved, and U.S.-Cuban relations deteriorated:
1855: Spain reinforced Cuba’s defenses.
1856: James Buchanan was elected U.S. president.
1858: Another attempt to buy Cuba failed.
Conclusion 🚀
The Ostend Manifesto boldly suggested that the U.S. should use money or military force to take Cuba. Pierre Soulé, by leaking the document, caused a public backlash that paralyzed any serious implementation of its proposals. In protest, Soulé resigned.
Had the plan been handled with more discretion, it might have received more serious consideration—but it ultimately revealed the expansionist, racially charged motives of the pro-slavery U.S. foreign policy establishment.
If you liked the article, please subscribe to reach 100 subscriptions.
Fascinating how much of early U.S. foreign policy was driven by the internal politics of slavery. The Manifesto wasn’t just about Cuba—it was about preserving the Southern economy and ideology. Definitely an under-taught episode in American history.