HIST 405 Week 3 Discussion: Manifest Destiny and the Mexican War of 1846

This week I chose the following events that I feel were the most impactful on the Westward Expansion during 1800-1848 were the Mexican War of 1846-1848 and the California Gold Rush. I feel that they both had a great amount of impact on the Westward Expansion because they were both opened the doors for explorers to seek out the new land opportunity not yet fully explored yet. But if I had to choose one out of these, I would have to choose the Mexican War of 1846-1848, because if it wasn’t for the U.S, taking over control of the Mexican land; California, Nevada, New Mexico, Arizona, Utah and parts of Colorado and Wyoming, we wouldn’t have had the advantage of having the land to explore. As U.S. tried to gain the Mexican land peacefully and avoid conflict, it was unfortunately not obtainable this way. Troops were sent to Texas and tensions rose higher between the two countries, leading to the  Mexican military firing upon U.S troops on American soil, , this started the Mexican-American War of 1846-1848 according to American History (2015).  As noted by Corbett et al. (2014), when Stephan Watts Kearny, General of the Army of the West went to move towards the take over of California, he came to found out that it was already in American hands, by U.S settlers that were notified of the declaring of war on Mexico, set sail to rush to California. There they were able to overtake the land and establish settlement in Monterey, it was then placed in the hands of the navy and Kearny who at that time was in charge, appointed himself as the Governor of California. With this in place, it led to other small quarrels and the overtaking of other cities/towns within the surrounding land. Corbett et al. (2014) noted that eventually Mexico and America came to an agreement were Mexico ceded to American, called the Mexican Cession which was the conquest of the land west of the Rio Grande River including the states listed above. This to me helped American gain the access needed to this undeveloped and underexplored land and open the doors to the people of the states to expand Westward to develop and settle. If it was not for this War occurring, then the settlers James Marshall and his partner John Sutter would not have migrated to the American River where they built a sawmill on the south-fork, where they discovered gold. This led to the news of gold in California to spread like wildfire and cause a huge rush of American’s to head West, making the expansion of America reality.

The effects that the Mexican War of 1846-1848 and California Gold Rush had on the ideology of the Manifest Destiny were in my opinion huge.  The Mexican War of 1846-1848 had opened the opportunity for American’s in the East Coast and the Inland states to expand and move towards the West Coast, being able to seek out new land and opportunities. According to American History (2015), many believed that Manifest Destiny was the U.S. military’s reason for action in the war, and that it was the U.S divine mission to obtain this land out to the west so that they could out reach to the remote corners of the continent to spread civilization and democracy. The California Gold Rush I feel was like a bonus to expanding the civilization in the West, fulfilling the ideology of the Manifest Destiny. Corbett et al (2014) describes, once people started to gravitate towards the newly acquired territory, it grew from thousands to 10,000 people, helping the economy grow by opening stores and saloons and even opening libraries, stage lines, fraternal lodges, acting companies and establishing newspapers in the area.  Therefore, I feel that this significant event of the Mexican War of 1846-1848 and the added event of the California Gold Rush really fit the ideology of the Manifest Destiny.

Corbett, P.S, Volker, J. Lund, J.M., Pfannestiel, T., Waskiewicz, S., Vickery. P. (2014). U.S. History.

OpenStax. Houston, TX. Retrieved from:

 https://openstax.org/books/us-history/pages/1-IntroductionLinks to an external site.

“Mexican-American War.” Issues & Controversies in American History, Infobase, 2015. American History.     Retrieved from: https://online.infobase.com/Auth/Index?aid=239824&itemid=WE52&articleId=1009480Links to an external site.

Louisiana has a few different influences, as Spain, France and United States controlled the territory. To increase the land of the United States, the Louisiana Purchase was made by Thomas Jefferson. This land was purchased for a low price from the French. Per the text, “…the Spanish had ceded Louisiana (and New Orleans) to France. In 1802, the United States lost its right to deposit goods free in the port, causing outrage among many, some of whom called for war with France” (US History, 2019). Hence this was an important purchase for the United States economy.

The Lewis and Clark Expedition went to unravel the value (“…trade routes”, US History 2019) of this new land by documenting and charting its contents. Native Americans helped Lewis and Clark with food and to travel through the territory as they created maps of the area showing the route, animals and plant life. Per the article, “The sight of This Indian woman, “Clark wrote as they met tribe after tribe on the Columbia, “confirmed those people of our friendly intentions, as no woman ever accompanies a war party of Indians in this quarter” (Duncan, 2004). Lewis and Clark went around letting the tribes know that the land was owned by big chief (United States). This expedition gave out gifts to show peace. This did not make sense of course as, the theme of taking land and limiting livelihood for one group was prosperous for another. The Teton (Lakota tribe) did not agree as easily because the gifts were not enough. The expedition felt the Tenton’s were not subservient enough as they demanded more than the other tribes. The Louis and Clark Expedition was the most valued as it opened up trade increasing profit for the United States.

The Missouri Compromise was really who had the ruling power to elect the president. The more slaves in a state gave more voting power. This then became a conversation of injustice of a race of people, which led to the Missouri Compromise. Missouri was allowed to keep people as property even though it was a Northern state.  

The Manifest Destiny only shows that greed and the need to control leads to devaluing of human life. Per the text, the “manifest destiny [describes an idea that it is necessary for the] white Americans [in the] United States [to expand and impose its beliefs on all others by] divine right and duty spreading Protestant, democratic values” (US History, 2019). I have to ask myself what does “democracy” mean and how it deemed useful.


Dayton Duncan. (2004, August 16). The living, breathing natives that made Lewis and Clark. High Country News. https://www.hch.org/issues/280/14923

OpenStax. (2019). U.S. history. OpenStax CNX. Retrieved from https://cnx.org/contents/p7ovulkl@6.18:gMXC1GEM@7/Introduction

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