The Ostend Manifesto, a.k.a. Ostend Circular, was a document written in 1854 that described the rationale for the United States to purchase Cuba from Spain while implying that the U.S. should declare war if Spain refused. The Ostend Manifesto was a document written on October 9, 1854 in Ostend, Belgium. The document was written by U.S. diplomats, James Buchanan, the U.S. minister to Britain, John Young Mason, U.S. minister to France, and Pierre Soulé, U.S. minister to Spain. An attempt to expand U.S. territory, the Ostend Manifesto pushed for Spain to sell Cuba to the United States for $120 million dollars. The document also suggested that if Spain were to refuse, the U.S. would use force as an effort to get them to agree. Intended to be a secret, the document leaked and was eventually made public. Although it was primarily an attempt to expand U.S. territory, the document also caused uproar against antislavery groups because Cuba was already an established slavery territory. The Ostend Manifesto was declared unconstitutional due to the Fugitive Slave Law that was passed as part of the Compromise of 1850; therefore Cuba did not become a U.S. territory.