How did the United States gain control over the territory from the east to the west coast in the 19th century?

The Monroe Doctrine paved the way for the United States of America to expand their boundaries. The idea of expansion and land ownership were deeply embedded into the American way of life. It is critical to note that the Monroe Doctrine was not the first American document to display Americans urge for more land, being twenty years previous they just made their most grand purchase of land (Lousiana Purchase). The aspect of adding more land into the country fulfilled the ideology that many of the founding fathers saw to be the duty of God’s chosen people. Their need to purchase more territory stemmed from the ideas of America's Manifest Destiny. The Latin American countries that were immensely affected by the benefits of America through utilizing the Monroe Doctrine included Mexico, Cuba, the Falkland Islands, and Gran Colombia.

Notes about the battle positions of American and Mexican armies in Rio San Gabriel.

Report about the boundary line between Mexico and the United States after the Treaty of Guadalupe Hidalgo.

Mexico was regarded as a great benefit for multiple reasons. First and foremost, the United States decided to intervene in Mexico, which led to gaining more Western land. When Mexico denied the purchase of what is now known as California, Oregon, New Mexico, and the rest of the Southwest by the United States, President James K. Polk requested troops to be sent to Mexico. The Monroe Doctrine allowed the United States to intervene in Latin America, and it justified the Mexican-American War. By choosing to intervene in Mexico, the United States gained Texas, California, New Mexico, Arizona, Nevada, Utah, Wyoming and Colorado through the Treaty of Guadalupe Hidalgo.

Newspaper article showing US views on newly formed nation. 

Painting of the USS Maine. 

The Monroe Doctrine held a vast impact on the relationship with Cuba because the United States demanded to be left out of Spain’s involvements with other countries. The decision then became a great advantage for the United States because they took control of Cuba and guaranteed its protection. In particular, a political group called the Young Americans wanted to gain Cuba as a state. They wanted this in response to California becoming a free state, and the South wanted to equalize the number of free and slave states in the Union. At first they wanted the president to buy it, but when this failed they called for it to be taken by force; a demand that was widely condemned by those in the United States and abroad.

Map of the Falkland Islands

The Falkland Islands started out as a penal colony in the middle of the Atlantic Ocean off the coast of Argentina. Geographically speaking, the Falklands would belong to the Argentinians. In 1831, the United States had to deal with Louis Vernet from Argentina arresting American sailors in the region.  Andrew Jackson sent troops to capture Vernet, destroy the Argentinian port on the island, and set the port free from Argentina’s control. Two years later, the British returned and began to use the port on the island as a naval outpost. The British wanted the Islands to be able to maintain their naval superiority and trading empire in the Western Hemisphere. The United States did not see the British as a threat because the British supported the Monroe Doctrine; however, the Falklands were in the Western Hemisphere, and the British were directly involved in colonizing it, which was a direct breach of the Monroe Doctrine. The Falkland Islands are roughly the size of Connecticut, but are conveniently located near a major shipping lane. So, if the British were to decide to cut off the East Coast from the West Coast, they could easily do it by using its naval superiority to blockade the area off.

Flag of the newly formed nation Gran Columbia 

Gran Colombia was of vital importance to the United States because of the strategic interests of having good relations with the country that controlled the Panamanian Isthmus. This area of land was very important to America because it was the best way to access the Pacific Ocean. In the 19th Century, it was becoming increasingly imperative to gain lands in the West, and this thin stretch of land shortened the travel time by boat from the West Coast to East Coast in half.5 Additionally, the Isthmus was not only important to the United States, but it was also crucial to worldwide trade. Clearly, having good relations with Gran Colombia was necessary to have control over the Panama region. Gaining land and control over Latin American countries lead for the United States to also be able to benefit economically.

Monroe Doctrine's affect on Land/Territory

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What events contributed to US expansion?

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