In the 1840s the territory of the United States of America experienced a massive and quick growth. Within only four years the size of the country doubled. Then more lands were annexed. Overall the country grew by about sixty per cent (Haynes, par. 1). This process started to make sociological influences. The United States developed moods and movements that saw this expansion as a political destiny of the country. According to these ideas, the United States was meant to take over the whole continent. Of course, these moods had opposing forces that were warning about the increasing risk of war with neighboring nations. There also were opinions supporting the imperialist ideas, but stating that military forces were not the right tool to achieve this goal, because other nations and lands would want to join the territory of the United States over time. The expansion was dictated by the imperialistic moods of the whole world. The United States was not short on lands, yet the annexation of new territories was seen as the only way to survive in the power race of the world and the necessary source of political and economical strength. This is how the concept of Manifest Destiny occurred. Westward expansion was the reason of the war between Mexico and the Unites States. The annexation of Texas by the US caused arguments over the territories and borders. Texans claimed some of the lands that Mexicans considered as their own. The war lasted for a year and a half, the United States was much more powerful, so as a result, Mexico had to give up more than half of its territory, the peaceful agreement between the two countries stated that the land will be given away for fifteen million dollars plus the sum of debts Mexico owed to the United States. The question of slavery abolition was raised during the expansion, the US government made promises that there will be no slavery on the annexed territories. The arguments over slavery put the beginning to the Civil War in the United States. The expansion served to unify the nation of the USA, but at the same time it served as a cause of a major conflict between the country’s citizens. First of all, this conflict touched the rich and the poor, the gap between the social classes grew rapidly because of the problems in the crops market and farming. There were too many farm states, which led to overproduction of crops. Besides, the size of the country made the transportation of the crops very expensive and long. Another aspect of national division of the United States that happened due to the expansion was the conflict between the Native Americans and the non-native citizens. The number of people dwelling on the territory of the United States grew, and because of that reservations were forced to move from their lands. This led to armed confrontations between the non-native military forces and Native Americans. The process of westward expansion was complicated and massive. It had its advantages and disadvantages. The leaders of the US were hungry for new territories and more power, but they also had to deal with more problems and conflicts that came along with the diverse and multinational population driven by very different needs and interests. Work Cited Haynes, Sam . M