“The South!” The poor South! God knows what will become of her now! » (Doc E) These were the last words of John C. Calhoun on March 31, 1850. As these words show, Civil War was predictable after the Mexican-American War. Although it was a great victory that nearly doubled the size of America, rage and fear were caused by sectionalism in the nation, which sparked the start of the Civil War. From the election of James K Polk to the succession of South Carolina (from the union), the nation collapsed, no matter who tried to preserve the union (Abraham Lincoln's primary goal before the civil war was to preserve the union no matter what). President James K Polk, who served only one term, was probably one of the most influential presidents of the United States. He had mandated the famous Manifest Destiny. Manifest Destiny convinced Americans that they were supposed to expand westward because it was a mandate from heaven. The families had traveled to the Pacific lands. In doing so, they drove Native Americans and Mexicans from their lands. This action was one of the catalysts for sectionalism in the nation and a direct cause of the Mexican-American War. President Polk wanted expansion, which led to much conflict. Polk had added Oregon, California, New Mexico and Texas. For the union, Texas was the most problematic country, because it had started the war with Mexico. The annexation of Texas was a difficult task for several reasons. First, it took some time before the Senate finally agreed to annex Texas. This caused a bit of disorder in Mexico, as they did not accept Texas' independence from Mexico and feared that the Americans in New Mexico and California would also rebel (claim their independence). .... . middle of paper......The Ostend Manifesto was an event that showed that the South did not just want to maintain slavery; they also wanted to expand it. The next step in achieving this was to acquire Cuba, as there was slavery in that country. “I want Cuba and I know that sooner or later we will have to have it. I want Tamaulipas, Potosi and one or two other Mexican states: and I want them all for the same reason: for the establishment and spread of slavery. "- (Doc M) Senator Albert G. Brown (Mississippi), 1858 Three United States diplomats traveled to Belgium to draw up an offer of $20,000,000 for Cuba to Spain. (Doc I) “After we "We will have offered Spain a price for Cuba well beyond its current value" - (Doc I) The Ostend Manifesto, October 18, 1858Unfortunately for the South, this was never implemented in Cuba. is not even an English-speaking country and therefore could not be part of the United States..