By the mid-1840s, the United States was considered a "go-ahead" nation, a nation that looked ahead to a future of great possibilities for the nation and its people. While the United States was enjoying this new status, its neighbor to the south and west, Mexico, struggled to control the territory it had inherited from Spain, most of which bordered the United States in its northern and northwestern regions. Mexico tried to attain the power and influence that was expected with its title of "New Spain." However, Mexico did not have the resources to settle and protect all of the territory it possessed. Additionally, Mexico suffered from political divisions within its government.

As both countries developed their own identities, conflict between the two nations eventually ensued. The U.S. – Mexican War started in 1846 and ended in 1848. This was the first conflict that the United States fought on foreign soil. The causes of the war mainly originated within the state of Texas.

Click on each of the stars below to learn the causes of the U.S. – Mexican War.

Answer the following questions about the causes of the U.S. – Mexican War.

1. How did manifest destiny play a role in the causes of the U.S. - Mexican War?Interactive popup. Assistance may be required.
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President James Polk wanted to purchase the land southwest of the United States, which would fulfill manifest destiny by expanding the United States to the Pacific Coast.

2. How did the United States instigate the war between the United States and Mexico?Interactive popup. Assistance may be required.
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Polk placed U.S. soldiers in the disputed land zone. This instigated the war between Mexico and the United States.