The Ostend Manifesto was a major contributor in pushing the Northern part of America farther away from the South, mainly because the regions disagreed over the controversial topic of slavery. Many other events in the Incivility period were related to slavery, whether directly or indirectly. 

​

       The writers of the Ostend Manifesto attempted to justify imperialist expansion, and supported the South's decision to continue selling, buying, and using slaves for their own economical benefit. For this reason, the North -- along with the new Republican party that was formed in June of that year -- saw the Democrats as a controlling slave power. The fact that the Ostend Manifesto was secretly drafted without the consent of the entire country flamed this fire even more. 

​

       The Ostend Manifesto stated that the U.S. would take Cuba by force if needed. At that time, if Cuba were to be taken by the U.S., it would become a slave state belonging to the South. The North had a major problem with this, as they felt that the South was willing to go to war and risk lives over a potential slave territory.

​

​

​

​

​

​

​

​

​

​

​

​

​

       All of these feelings pushed the two American regions farther and farther apart, which eventually led to the American Civil War depicted above (1861-1865). With over 600,000 deaths, the Civil War is widely considered the worst war in American history (see Number of Military Deaths in American Wars below). 

​

       The presidency and administration of Franklin Pierce was also ruined due to the Ostend Manifesto, along with the Kansas-Nebraska act that was signed May 30, 1854. He lost the support of half the country, and of his own political party. This led to Pierce's defeat in the next presidential election, by none other than one of the very writers of the Ostend Manifesto, James Buchanan. James Buchanan would later be involved in other events within the period of Incivility, such as the Secession of North Carolina, the Dred Scott decision, and Bleeding Kansas.

​

       Although it may seem insignificant, this one document had a tremendous impact on the social and political atmosphere of the United States. It contributed to a major chain of events within the period of Incivility, leading to the Civil War which threw America into violent conflict for 4 years.