American expansionism in the 1840s was due to the need to move westward as the increasing American population grew immensely, new economic opportunities and most importantly due to the belief Manifest Destiny. Manifest Destiny was the belief that God had destined the United States to expand across North America from the Atlantic to the Pacific. Many Americans associated Manifest Destiny not only with territorial gain but also as a means to achieve freedom for the people. In order for the United States to expand westward, land had to be acquired either through war or through negotiations. Taking land from their rightful owners, in this case Native Americans, posed as a major problem in expanding westward. Dispute over land also led to conflict with natives and war with Mexico. Manifest Destiny was thought of to be a benevolent movement throughout the 1840s; however, the truth in reality was that it was aggressive in nature and just a term used to justify American imperialism at the expense of others. Americans took lands from people, especially Native Americans, without their consent and killed and subjugated those people and use Manifest Destiny to justify their actions which in itself was morally wrong. Prior to the peak of American expansionism and the main idea of Manifest Destiny in the 1840s, there were various attempts at expanding the United States westward that came at the expense of the Native Americans. Under Andrew Jackson’s presidency, Americans forced tribes from their homes, tore apart families, and murdered innocent natives to acquire their land. The Trail of Tears brutally forced thousands of natives to walk miles away from what Americans believed was their rightful land. The natives suffered as they had little to no rest, inadequate food, sickness and disease, which cause many to die along the way. The Indian Removal Act only led to the removal of Native Americans from their rightful homes, and resulted in the loss of innocent lives. This only furthered the desire to move westward as many Americans believed that Native Americans were an obstacle in expansion. To white Americans, the Natives were wasting the land that they could be using for cultivation thus the idea of America’s progression towards Manifest Destiny in the upcoming years was used to justify the unfair removal of Native Americans from their homelands. The Oregon Territory was claimed by both Great Britain and the United States at the time and proved to be more difficult to acquire. President Polk did not have any interest in going to war over the Oregon Territory thus he agreed to Britain’s proposal to divide the territory at the 49th parallel by signing the Oregon Treaty in which the United States would gain land south of the line. Tensions between white settlers and Native Americans in the Oregon territory grew as the growing American population began to move westward into the new acquired land. With the new settlers came diseases and in 1847, a measles epidemic broke out and killed nearly half the native population there. Marcus Whitman was a physician who was supposed to check the epidemic but was unable to do so, thus the native tribe residing in the area, the Cayuse, believed he was intentionally poisoning their people. They believed that by poisoning and killing the native people there, Whitman was trying to make room for white settlers to move onto the land. This caused the tribe to attack Whitman and his mission and resulted in a bloody massacre and the hanging of five Cayuse warriors by American troops. As punishment, the native people were relocated onto reservations and their lands were confiscated. Relations between the Native Americans and white settlers only worsened as a result of the Cayuse War. Although the United States did not go to war with Britain over Oregon, they went to war with the Cayuse tribe over the land. This ordeal would only lead to the fact that the United States would go to war with another country over expansionism. In 1846, the United States went to war with Mexico. The Mexican-American War fulfilled the belief of Manifest Destiny as the United States was able to gain land from the Atlantic to the Pacific Ocean due to Mexico’s loss in the war, resulting in them giving nearly half of their land over to the United States. The war occurred after the annexation of Texas to the United States in 1845. Mexico had never recognized Texas’ independence and only regarded it as a rebellious territory that they would able to reclaim; however, once the news about the United States annexing Texas came out, Mexico was far from happy. They cut diplomatic relations with the United States and conflict came about in regards to Texas’ boundaries. Mexico threatened war with the United States who tried to ease tensions by talking about negotiations for land, which failed as Mexico refused to compromise. A small fight broke out between American and Mexican soldiers along the Rio Grande in which the Mexican soldiers defeated the Americans. This was known as the Thornton Affair which led to President Polk’s call for war against Mexico. The war ended when Mexico ceded land over to the United States under the terms of the Treaty of Guadalupe Hidalgo in 1848. The Mexican War sparked a dispute over slavery upon the newly gained western territories between the North and the South. After the war, Mexico lost a large number of lives due to the battles fought and deeply humiliated the Mexican people as they were forced to give up their land to the enemy. It destroyed the honor, pride and dignity of the Mexican people and developed a resentment towards the greedy American people. Ultimately, America’s Manifest Destiny was aggressive imperialism in disguise of a benevolent movement. Prior to the peak of American expansionism, white Americans sought to expand westward onto native lands in which they believed were being wasted by Native Americans as they were not being used for cultivation. This led to the removal and relocation of these native people through harsh and unfair means, in which Americans justified their actions by claiming they were an obstacle in the progression towards fulfilling America’s Manifest Destiny. As the peak of American expansionism came towards the 1840s, the United States was able to acquire some Oregon land which was home to the Cayuse tribe. Tensions between Native American and white settlers only grew when white settlers brought in diseases that killed nearly half the native population in the area. These natives were stripped of their land and relocated which only allowed more settlers to move west. The Mexican-American war stripped Mexico of its lands and left the Mexican people with a loss of many lives and destroyed the national honor and pride they once held. Due to the greedy needs of white Americans for more land and the mindset that they were entitled and more superior than others, it came at the expense of innocent lives that left many with resentful feelings towards Americans. Manifest Destiny was morally wrong as it took lands from those without their full consent and killed and subjugated the people who had rightful claims to their lands. Although many may have saw Manifest Destiny as an opportunity to strengthen America as a nation, the means to get these lands came at the expense of innocent people and Manifest Destiny itself was really just aggressive imperialism in disguise as a benevolent movement.